Sci Foo for All?

Last month, I attended Science Foo Camp. Foo stands for “Friends of O’Reilly,” which means the event is sponsored by O’Reilly Media, Google, Digital Science, and Nature. Each year, some 350 scientists from around the world convene in California for a jam-packed invitation-only self-organized unconference with more free food and drink than entirely reasonable.

Based on the few things I’d heard about Sci Foo, I expected it to be Very Good. But I didn’t have any concrete goals or expectations. I was mostly honored to be invited and excited to take my first solo trip post-breastfeeding. So, how was it?

On the first evening, after dinner and a couple of orientation activities, everyone was invited to pitch a session, unconference style. Here is a small sampling of what we came up with: Are you an advocate or a scientist? How is peer review broken? Help science work better. Design your life. Equity in science. Looking for aliens in the universe. Astronomy for a better world. Fixing labor and training in science and tech. Your doctor learns from YouTube. Managing climate futures. Is the next step driven by big data or big ideas? The sixth mass extinction. You, some astronomers, and a planetarium. Collective cognition. I’m an introvert, help! Decolonizing science: how do we know what we know? Reaching the front page of the internet. What do we do about vaccine skepticism? Social media for social good. Light pollution ruins everything. What is the scientific journal of the future? Fully automated luxury feminism. The neural basis of consciousness.

An early iteration of Saturday’s schedule.

Wow. I wish I could say I made it to even half of these. In reality, up to sixteen sessions happened in parallel, and many morphed and combined over the course of the weekend. I attended maybe five of the ones I listed, plus several others. After dinner, folks hung around the open bar, chatting and playing games well into the night.

Everyone’s name tag included three “ask me about…” topics, which made it easy to strike up a conversation. I talked with a policy scientist who used to work on mouse hearts, an app developer who works to make video content skim-able, a material scientist who uses image processing to identify different plastics, a theoretical physicist who has developed a metric for prestige, and so many more. I stumbled into a conversation about neutron stars and gravitational waves. I joined an impromptu planetarium show and explained how the Kepler spacecraft found exoplanets. I learned how measuring things in the ocean can be even harder than measuring things in space. I told a 5 minute story about failure that I put together in 20 minutes during an evening “story slam” hosted by folks from The Story Collider. I learned that cancer researchers have at least as hard of a time getting funding as astronomers do. I ate an impossible burger just down the table from where its inventor was sitting. (It was fine.) I objected when a fellow attendee suggested astronomy was somehow removed from ethical or political issues—because it’s not—and listened as someone else argued that private space ventures are not exploitative (spoiler: he co-manages one). And I haven’t even begun to recap any of the 20-someodd 5-minute lightning talks.

There was never a dull moment. I was a little blown away that many, if not most, of my nominal peer attendees were professors. More than once, somebody was congratulated for recently getting tenure. When children came up in conversation, fellow parents took a moment to appreciate the luxury of a weekend to ourselves. People enjoyed hearing that I develop software for processing huge volumes of telescope images. They marveled at how much open source software astronomers have made and how its applications extend far beyond astronomy.

There was lots of free food, and I brought my kid’s friend “Shortcake” to send some fun photos home. Here, Shortcake is helping me with a liquid nitrogen ice cream snack.

At the end of Sci Foo, the organizers issued an open invitation to take the mic and reflect on a highlight of their weekend. After a few folks offered amusing or moving anecdotes, one particularly brave soul stepped up. “When you nominate someone to be invited for next year, consider choosing somebody that doesn’t look like you.” He said Sci Foo was one of the whitest spaces he had been in. I was momentarily surprised, because I had been glad to see at least some people of color in attendance. Then I remembered how skewed my perspective is. Any people of color at all greatly outnumber what I experience in my daily professional life. And he was right—an event that relies heavily on past attendee suggestions to invite new faces is probably not as diverse or inclusive as it should be.

One thing that stood out to me was a lightning talk about making a hologram out of sound. In essence, a team of researchers has figured out how to manipulate sound waves to be concentrated in a small area. The speaker showed a cool video demonstrating how these sound holograms can manipulate small objects without having to touch them. He talked about how this could have a huge impact in surgery and other medical applications, but said they couldn’t get any funding to work in that area, so his team works on interactive displays instead. I don’t have an issue with sound holograms being used to improve interactive displays, but I can’t help but wonder how many brilliant researchers have to forfeit potentially life-changing applications in favor of whatever some tech company will pay for.

The transition home after an energetic, collaborative, and invigorating event is always rough. This time, I could not stop thinking about who was not at Sci Foo, and how astronomy is not inherently a force that pushes everyone toward a better world. Who is not invited? Who is not in the room? Whose voice is not welcome or heard? Western science has historically done a poor job of addressing these questions, and while there have been some nudges toward inclusivity here and there, overall very little has changed. Sci Foo attendees have all achieved some degree of career success in STEM to even be invited, and it’s pretty clear we are failing people well before this stage.

I would like to find a way to bring the Sci Foo experience to scientists before they’ve “made it” enough to be invited to the main Sci Foo. I don’t have a plan for this yet, but I suspect it looks something like the ComSciCon franchise model. Connecting with like-minded people from all around the world has had a huge impact on my own confidence and success, and that was facilitated by social networks like twitter together with real-life events like ComSciCon well before I had any idea what my post-grad-school career could be. It is incredibly inspiring and motivating to see the real problems people are working on in a variety of disciplines, discuss how they are tackling them, and have heart-to-heart conversations about their challenges. Let’s find ways to facilitate this for more people.

Breast pump 2018: a year-in-review pseudo-paper


I’m going to give up pumping at work in 2019. I can’t wait! It may be a right-off-the-bat thing, or it may take a few weeks, we’ll just have to see. This post is a retrospective of my year-long pumping-at-work experiment.


Throughout 2018, I have spent an inordinate amount of my life thinking about breastmilk. My first child Skyler was born in September 2017, so specifically, I’ve been thinking about how to deal with breastmilk when I am away from her and how to ultimately get it safely back to her. I’ve been tracking everything in a Google Sheet all year, and now you get to see the outcome in this pseudo-paper blog post writeup.


Behold: two visualizations from my year of the breast pump!

Figure 1 – All pumped and consumed (bottle-fed) breastmilk in 2018. If it came out of me and went into a bottle or a bag, it’s in this bar graph. Spilled or otherwise discarded milk is not included, and was thankfully negligible.
Figure 2 – The same as Figure 1, but only for breastmilk that was consumed during M-F 9am-5pm while I was at work and milk that was pumped for intended consumption in the same workday timeframe. This typically meant the milk was stored in a refrigerator.

A few interesting trends stand out. First, you can pretty clearly see the two instances when I traveled away from Skyler in February and March (once for vacation, and once for work). It’s worth noting that she did consume breastmilk in the late February vacation “gap” in Figure 2, but it was freezer milk, so it doesn’t appear here. There is a corresponding “bump” in Figure 1, which includes all pumped and bottle-consumed milk.

There are regular gaps on weekends and slightly larger ones that correspond to holiday weekends or vacations/trips. On those days, I nursed instead of pumped. Early on, Skyler always wanted more milk than I could pump during the workday (more on this in a bit). You can also see that the quantity of breastmilk consumed and produced gradually decreases with time! Skyler began eating some solids in April, so it’s interesting to see the lag between that introduction and the subsequent milk tapering.

Figure 3 shows the changing quantity of freezer milk over time. The space between the two cumulative distributions represents my freezer stash. Until late June, in addition to pumping milk at work for Skyler to consume the next workday, I was also pumping a few ounces in the morning for the freezer. (Somehow I singlehandedly managed to nurse, change a diaper or two, shower, pump, eat breakfast, put clean clothes on myself and a baby, and keep said baby mostly entertained each weekday morning between 7–9am. My husband was in charge of evenings.)

Figure 3 – Cumulative distribution of frozen breastmilk. The farther apart the lines, the greater my freezer reserve stash.

If I had evening commitments that prevented me from nursing at bedtime, Skyler would have a bottle made from frozen milk and I’d nominally replenish it in a late-night pumping session. In reality, she was always eager to drink a bit more milk from a bottle than I could readily pump. The pre-work pumping sessions from January–July helped make up the deficit.

Figure 3 also shows the two trips I took in February and March, as well as an early summer freezer surplus followed by dwindling supplies that eventually settled into a new, smaller equilibrium. My period returned in early August and does seem to have a small negative effect on milk production, but this short-term effect isn’t readily apparent in any of the Figures. Figure 3 doesn’t show any of the pumping I did prior to January, which was obviously nonzero! I worked hard while Skyler was 1–3 months old (October–December 2017) to build up enough of a freezer stash to support both my return to work and my eventual trips away from her.

Pumping Technique

I use a Spectra S1 breast pump (actually, two of them; one lives at home and the other at work). A “pumping session” consists of taking my pump and peripherals to a private non-bathroom location, attaching a Bravado pumping bra accessory to my nursing bra, ensuring the pair of bottle assemblies are clean and put together correctly (each assembly consists of a flange + duckbill valve + backflow protector + bottle), lining up the flanges on my breasts, connecting both bottle assemblies to the pump with tubes, and applying a bit of heat via microwaved flaxseed pillows or a battery-powered hand warmer.

One set up, I turn the pump on to the initial massage mode for 30 seconds or so before switching to the express mode. Early on, I used it at suction level 2-3 at 46 cycles/second, but more recently I use it at level 4 at 50 cycles/second. I pump for about 20 minutes with occasional hand massaging. Otherwise I am “hands free” and able to do something on my phone or laptop. I always get more milk from my left side than my right. I time the pumping session with the Hatch Baby app.

When I’m done, I disconnect everything, pour the milk into a single bottle (for refrigeration) or bag (for freezing), and put all the dirty parts away. If pumping more than once at work, I refrigerate the dirty parts to use at the next pumping session. The backflow protectors stay with the pump since they don’t contact milk and don’t need washing regularly. Everything else gets washed by hand at the end of the day. Finally, I plug the pump back into an outlet to charge for the next use.

Lessons Learned

You get to experience a lot of extreme scenarios with a new baby. I had no idea if nursing or pumping was going to work for Skyler and me, but I wanted to give it a solid try. She got formula a couple times in the early days (September–October 2017) when my milk was slow to come in, and again during my February trip when the freezer stash ran critically low. We visited lactation consultants several times in 2017, which was essential.

Breastfeeding is learning an entirely new bodily function when you’re more sleep deprived and hormonally unbalanced than you’ve ever been. It’s hard. It’s kind of like you’d never urinated your whole life and now you have to figure out how toilets work on zero sleep, only you love the toilet and it needs your urine to survive and your bladder really doesn’t like being overfull.

Anyway. As if all that weren’t enough, then I went back to work! For me, that happened when Skyler was just over 3 months old, in January. For the next 6 months, I spent three ~20 minute sessions pumping milk at work (and that doesn’t include the setup, teardown, and additional time needed for all the context switching). I used a small windowless telecon room very close to my shared office, and nobody ever barged in on me! One time the lock on the door broke and got stuck in the locked position, so my officemates kindly vacated our office when necessary until it was fixed. My “Pumping in progress / Do not disturb” door sign definitely paid for itself multiple times over.

When Skyler was 9 months old, in June, I switched to pumping twice daily at work, and felt like an almost normal functional human for the first time in ages. It is hard to overstate how restrictive it is to always be planning pumping sessions into your day… around meetings and meals and social events and heaven forfend you ever need to use the bathroom! When she was around 13 months, in October, I went down to once daily, which is once again an order of magnitude less restrictive than before.


My husband and I took a week-long cruise vacation in February and left Skyler with her grandparents. It was one of the hardest and best possible things we could have done (and I can’t wait to do it again in 2019, but without the non-trivial side quest of bringing breastmilk home!). Exclusively pumping feels very different from nursing or even a combination of nursing and pumping, but it does the job if you’re consistent. You have to be so consistent. I pumped on a catamaran, I pumped in a restaurant, I pumped during a concert. That week away deserves its own writeup, but instead I will point you to the amazing Experiments in Pumping blog, which is all about traveling pumping and getting pumped milk home. We lucked out and nobody cared when we checked a bag containing a soft-sided cooler full of chilled milk and ice in bags. I later learned you are not allowed to check “wet ice” (as opposed to dry ice, which is OK in certain situations). I don’t know what I would have done if that bag hadn’t made it home… best not to think about it.

I also went on one work trip in March without Skyler. I made my pumping needs known and was able to get a hotel room with a refrigerator without much difficulty. The Caltech facility hosting the meeting (the Cahill Center) had a very good lactation room, and I only had to jump through a few hoops to get access to it. Most of the main events were being live-streamed and I really appreciated being able to tune in remotely. I used MilkStork to ship breastmilk home and my work paid for it.

I went on one additional work trip in August, which was a full week (versus just two nights in March). For this trip, I arranged to bring along Skyler and my husband. Skyler’s grandparents opted to come too and babysat for free so my husband could work remotely while I attended the conference. The logistics for this trip were very challenging and we wound up paying over $1000 out of pocket (not counting the cost of Skyler’s grandparents coming along). On hindsight, I would have rather skipped it.


It is worth noting this retrospective only captures part of my breastmilk story with Skyler. Figure 1–3 don’t include the most tumultuous first few months, and they don’t capture any of the nursing we have done throughout her life. She nurses morning and night, presently for about 12 minutes (6 minutes on each breast). In the past, those sessions could easily stretch to 30 minutes or longer. At some point in the year (I believe between July and October), she stopped nursing when I got home from work. As of December, she gets breastmilk three times daily: first thing in the morning around 7:15am, midday before her nap, and around 7:45pm immediately before bed.

Overall, I am very glad my breastfeeding and pumping journey with Skyler has gone as it has. It has been a very positive thing for both of us, despite the incredible time commitment, cost, and complex logistics.

If I had to do it over, I would probably make some small changes, such as which bras to use, insisting on a separate fridge at work, choosing a smaller/more portable secondary pump, or skipping a work trip. But overall I did a lot of research, did my best to listen to my body and to Skyler, avoided mastitis, and felt like I made well-informed choices. I am particularly thankful to have the flexibility, resources, and support to follow through on those choices, and I recognize many birth parents do not. This includes choosing to gradually ramp down my nursing/pumping as Skyler gradually gets more of her nutrition from solid foods past the one year mark. It’s been quite a journey, and we’re both better for it.


My husband cleaned all of the bottles, valves, flanges, and miscellaneous “pump parts” the vast majority of the time. He also does most of the cooking and all of the dishes. And he had zero overnight work trips in 2018. Nothing written here would have been possible without him! Skyler is pretty great too; she was born on her due date and I am thankful the difficulties we had with breastfeeding were reasonably standard (though, for the record, that doesn’t mean they were easy). If you have a breastfeeding and/or pumping parent in your life, please tell them how much you appreciate their hard work, whether that work involves parenting, the workplace, or something else.

It’s time now for me to tell you

The following is of a more personal nature than I usually share on AstronoMerrdiff. If you would like to reach out and discuss it further, I welcome you to contact me by email.

“Becoming a parent will change your life.”

It’s something all expecting parents hear with increasing regularity until their child arrives. And it’s true! I believed it before I became a parent, and I believe it now. But believing something intellectually is different from living it with your heart.

Figuring out parenthood involves a lot of reflecting on childhood.

My first glimpse of how a parent’s universe centers their child came when my mother was dying. She set three goals: short-term, mid-term, and long-term. I was floored to hear they all had one thing in common. Me. She accomplished the first, which was to see me graduate from high school. (She didn’t live to see me graduate from college, and I haven’t traveled to space just yet.)

With my mom at high school graduation. June 2004, Richland, WA.

Parenthood is also interesting from a biological perspective. From early in pregnancy, fetal DNA makes its way into a parent’s tissues, and it never leaves. Growing a person inside you is wild. Keeping that tiny person alive after they are born while recovering from labor and delivery is the hardest thing I have ever done — and my experience was uncomplicated with loads of support throughout.

(I cannot fathom how people do this in less-than-ideal circumstances, except I can; they do it the same way people do anything in less-than-ideal circumstances, one bit at a time, one foot in front of the other, breathing in and out, while others marvel at their fortitude and survival.)

As a new parent — I can still claim that one year in, right? — I have officially joined the ranks of folks who proclaim that becoming a parent changes your life. I’m sorry I can’t be more specific. It has a lot in common with the experience of somebody close to you dying. You keep being you, the sun keeps rising and setting, this is just a part of life, nothing fundamental has changed. And yet, everything has.

Holding my baby Skyler one day after birth. September 2017, Seattle, WA.

I thought that about covered it: life-changing family-related death and birth experiences.

My mom died. Thirteen years later, I had a baby. Check.

So you can imagine my surprise when I learned one more paradigm-shifting family factoid: it turns out I have a biological half brother.

Let’s get a few details out of the way. We share a mother, he’s 18 years older than me, and he lives in Indiana with his wife and two teenage kids. I had no clue he existed until March 2018, nearly 14 years after Mom died. Turns out family secrets are a thing!

Learning about this feels like living a fictional tale.

“My long-lost half brother”… Come on, really? But this has been one of those page-turners that leaves you feeling a little more whole by the end, even if you’re not entirely sure what is happening from one chapter to the next. I’m not mad or resentful toward my mom. I understand why she kept this a secret from me, even as I wrestle with her decision.

More than anything, I marvel at her strength and fortitude even more than I already did.

When a loved one dies, they are frozen in time. They leave behind not just memories, but also threads. Connections to the lives of everyone whose life they touched. Early in the grieving process you might be consciously looking for threads everywhere, wishing you could gather enough to sew a proper blanket and don it forever. (This is particularly apt as my mom was an avid sewer.) As time passes, you are still searching for threads, but it is involuntary. You don’t even realize you’re doing it.

Over the years, threads pop up sporadically, whenever you forget about them. A song here, a smell there, a familiar haircut or turn of phrase. Learning that my mom had a baby 18 years before me — when she was only 18 herself — was one of those rare, precious times when some of the threads lying about neatly stitched themselves right up. A piece of my mom I didn’t know was missing suddenly came into focus and made more sense. Of course she felt so strongly about this; no wonder she reacted like that.

For context, I grew up an only child. Like only children everywhere, I occasionally wondered how my life would be different if I had a sibling. As a teen and young adult, I asked each of my parents why they decided to have just one child. The gist seemed to be that Mom kind of wanted me to have a sibling, since she really valued her relationship with her sister. Dad thought I turned out pretty well and didn’t want to “roll the genetic dice” a second time.

Me as a young child with my mom. Circa 1989, Grosse Ile, MI.

But there was so much more to the story…!

My mom got pregnant as a 17-year-old college freshman in Illinois. She decided to put the baby up for adoption, sever all ties, and work extremely hard to maintain her scholarship since she could not otherwise afford college. She took a quarter off to work as a live-in nanny during the final months of her pregnancy, and gave birth in December 1968.

She continued dating the baby’s father for another year or two, but they did not marry. She graduated on time with a Bachelor’s (1971) and then a Master’s (1972) in journalism from Northwestern. She later married a different man, discovered he was cheating on her, and divorced him. She married my father in 1983 and I was born in September 1986.

Throughout this time, she excelled in her journalism career, working as a newspaper reporter in Miami, a TV producer in Greensboro, and a reporter, producer, and director at TV stations in Seattle and Detroit. She was laid off while pregnant with me in Detroit, and decided to stay home while my dad continued working as an engineer. The three of us moved to Richland, Washington in 1990 for my dad’s work. Mom considered looking for a job, but the local newspaper and TV stations were small and she decided to continue being a stay-at-home parent.

This arrangement continued until she developed advanced kidney cancer while I was in high school and my father retired to care for her. She died in August 2004, two months after I graduated from high school and two weeks before I started college.

As I understand it, Mom was adamant that I not repeat the cycle of getting pregnant in college, and the best way to prevent this was to keep her story a secret. Of course her sister knew, and my dad knew, too. Mom thought often about her son, but never learned what happened to him. She focused all her energies on her present-day family (Dad and me) in a way I now appreciate even more.

When it was clear her health was deteriorating in 2002, she wrote an anonymous, to-the-point letter for the adoption records. “I have looked for your face in the crowd for over 30 years,” she wrote. “I do not want you to get in touch with us … My daughter is a wonderful person, who has a very full plate and does not need any additional stress.” The letter concludes, “It seems it’s time you knew all this. At least, it’s time now for me to tell you.”

I will let my brother Tom tell his own story, but for a few details.

First, he was adopted as an infant by a loving family, and did not find the letter Mom left for him until 2006, two years after she had died. Second, Illinois State law changed in 2010 to allow adoptees access to original birth certificates and adoption records. When Tom submitted a request, he learned Mom’s name, found her obituary online, and then found…me. He respected Mom’s wishes to not contact me, and enjoyed my public internet persona from afar.

At some point, Tom decided to send a DNA sample to AncestryDNA hoping to learn about his genetic history. He wasn’t thinking much about the feature that automatically combs through the DNA database to find likely relatives.

My Aunt Pam, on the other hand, was thinking about AncestryDNA’s database of likely relatives. She enjoys piecing together elusive parts of her (my!) family tree, and using her DNA was a logical next step. So when she saw a notification in January about an “extremely likely” match, she fired off a quick inquiry.

“Which side of the family are you on, Linwood or Sanders?”

The response came promptly. “I don’t know, I was adopted.”

Pam immediately realized who she had stumbled right into.

With that small online exchange, my world shifted. Pam and Dad exchanged messages and phone calls with Tom, conferred with each other, and ultimately decided I should be told. A couple months later, Dad did the telling in his typical drawn-out-story fashion.

“Your mother,” he began, as we sat facing each other in my living room.

OK, yes? He spun a tale of her academic prowess, her family’s limited means, and her tendency to have steady boyfriends, including early in college. She got pregnant, he revealed, and as this was before Roe v. Wade, she was given two options: an address in faraway Mexico for an abortion, or the phone number of a local adoption agency. He paused to ask if I would like to guess what she chose.

“You’re not making this sh*t up, are you?! No, I don’t want to guess, I would like you to continue the story.”

Tom and I exchanged emails and spoke on the phone shortly after, and he and his wife came to meet Pam and me (and my baby) in Seattle in July. We had a truly wonderful time. If I’m being honest, I’m a little disappointed Tom doesn’t resemble Mom more. But there are so many threads. It is a fascinating case of nature vs. nurture.

My mother’s sister Pam, Tom’s wife Shawn, Tom, me, Skyler, and my husband Mike. July 2018, Fisherman’s Terminal, Seattle, WA.

The most striking thing to me is how easy Tom is to talk to. He majored in journalism, like both his biological parents, but doesn’t work in that field. He is a conservative midwestern sports fan, which are three things I am decidedly…not. But we are both parents, and we are biological half siblings, and everything about that is remarkable.

Does knowing a thing change its reality? Quantum mechanics suggests it may. Becoming a parent certainly changed my mom’s life, but not in the way I originally imagined. I still feel like an only child. And Tom’s family is still Tom’s family.

How I wish Mom could be here to witness this incredible reunion! She didn’t want me to know about her college pregnancy when I had yet to experience either college or pregnancy. But I have a PhD now, and a child, and I think she would be relieved to know that I know.

I am thankful the threads assembled as they did, and not as uncomfortable, unearthed questions decades down the line. It is a blessing that the only sad part of this story is that Mom is dead.

Becoming a parent changed my life overnight, but becoming a sibling is just beginning.

Gaia Sprint Seattle

Long time no blog!

Let’s see, what has happened in the last year…

  • I grew a small human inside me and gave birth to her and have taken care of her for nearly nine months! Skyler was born in September 2017. I didn’t do any of this singlehandedly and am so thankful to be supported by numerous parties: my husband, our families, friends near and far, our church community, my colleagues, and my employer’s paid “faculty sick leave” which thankfully applies to birth parent postdocs like me. (UW’s leave policy is wholly inadequate for many other postdocs and I recently joined a working group tasked with helping improve it.)
  • I’m still at the University of Washington working on Data Management for the LSST Alert Production Pipeline. This means I spend most of my work time on software development and thinking about processing large quantities of digital images taken by telescopes.
  • Earlier this month, I took a break from all that to do some science! Officially I get to spend 20% of my time on science (and the remaining 80% on LSST things, which is not NOT science, but is very much its own thing). It was overwhelming and also very fun to spend an entire work-week diving into an unfamiliar dataset with my scientist hat on.

This post is about that last thing.

More specifically, The 2018 Gaia Sprint: Seattle Satellite Edition, hosted by the eScience and DIRAC Institutes at UW.

Gaia… what, now? Gaia is a spacecraft that was launched in 2013 by the European Space Agency. It has observed over a billion stars. There have been two “data releases” so far, when large quantities of data were made public, referred to as DR1 and DR2. The data come from three primary instruments, roughly speaking: positions of stars (astrometry), apparent brightnesses of stars (photometry), and radial velocities of stars (via spectroscopy). If we have all of this information at once, to high precision and for over a billion stars, we can learn all kinds of interesting things about our stellar neighborhood.

One pitfall of surveys that collect data for billions of stars is they tend to assume my default that every object is a distant, non-varying, solitary, constant-color, stationary star. Ha! That would be a boring Universe indeed. So, I decided I wanted to search for binary stars in Gaia DR2. There are many ways to approach this: for starters, you could isolate the so-called binary main sequence, or you could look for stars that have large proper motions or radial velocities. I focused on radial velocities.

I began with a sample of about 7 million stars created by Tommaso Marchetti which all have what he calls 6D data. This means their position in 3D space plus their velocity (both in the plane of the sky and in the radial direction) has been measured by Gaia. I then kept only the stars with at least 6 radial velocity observations which have a standard deviation of 10 km/s or more. This left about 300,000. Finally, I cross-matched this list of stars to see which of them had been observed by APOGEE, an infrared spectroscopic survey that is completely separate from Gaia. There were roughly 2800 stars left.

Screen Shot 2018-06-26 at 1.26.00 PM.png
Seven million Gaia stars with 6D information plotted on a color-magnitude diagram (purple). Overlaid in yellow/orange are those stars with a large standard deviation in radial velocity (about 300,000).

While it’s certainly reasonable to say “stars with large changes in radial velocity are likely to be in binary systems,” and to create a list of these stars, we still need a way to see if we’re right or not. This is where APOGEE comes in. While Gaia did use spectroscopy to measure stellar radial velocities, DR2 does not include the actual spectra. They distill all that information down into a single number (with an error bar, of course) for a fraction of the over 1 billion Gaia stars, and throw out any that push the edges of what the pipeline that goes from spectra → single measured velocity expects. APOGEE, on the other hand, has publicly available spectra right now! Unfortunately, fewer than 1% of the 300,000 high-Gaia-radial-velocity-standard-deviation stars were observed by APOGEE, but that is still way more stars than I’m used to working with.

OK, so what do those 2800 APOGEE spectra look like?

Are they binaries or not?? How can we tell?

Screen Shot 2018-06-26 at 1.30.55 PM.png
Small regions of infrared APOGEE spectra for a handful of my Gaia binary candidates. If a star was observed by APOGEE multiple times, all of its spectra are over-plotted in different colors with a small y-axis offset for clarity. Many of the spectra do seem to exhibit rotational broadening or double-lined profiles.

The “smoking gun” of stellar multiplicity when looking at spectra is individual spectral features dancing left and right over time due to the Doppler effect. In some cases, you would expect to see a pair of absorption lines where there would normally be one, and they would move back and forth in opposite directions. (This is called a double-lined spectrum). Unfortunately, all of the spectra have been automatically shifted to zero radial velocity by the APOGEE processing pipeline, so further work is needed to examine the spectra before this shift is applied. At a glance, though, many of the spectra appear to be fast rotators, which can be related to binarity, and some of them do look to be double-lined.

And that is where the week ended.

This project is not really done, but it came a long way in just a week. I owe a big thank you to the Gaia Sprint Seattle organizer, Jim Davenport, and to Trevor Dorn-Wallerstein and Jennifer Sobeck, who were both excellent collaborators. Along the way, I learned a lot about the idiosyncrasies of astronomical data access, and catalog queries in particular. Most of my stellar astronomy research has focused on fewer than 100 stars. That meant I could keep track of each star’s data in something akin to a spreadsheet, even if it was a bit tedious, and that I was mostly on a “first name basis” of familiarity with each of the stars I was studying. This mode of thinking is becoming less and less applicable as large surveys like Gaia and LSST come online! So if nothing else, spending a week at the Gaia Sprint was an excellent crash course in “working with large datasets is less intuitive than you think.”

My Science Talk NW presentation

Last week, I attended Science Talk Northwest in Portland and participated in their Science Communication Contest. Presentations had to fit within three minutes (with a 30 second grace period), you could not use any slides, and you could use a prop. The competition was specifically for “trainees,” who ranged from undergrads to postdocs.

I didn’t win, but I did make it into the Top 10! The winner and runner-up both did outstanding jobs and used props very creatively (did you know a super soaker is like a placenta, and that drumming can relate to personalized medicine?). I will have to think about how to incorporate props into future presentations about LSST and astronomy. I felt much more solid about this talk than previous three-minute slide-free talks I have given, however, because I began preparing it more than a couple days in advance and incorporated intentional gestures to help remind me what came next.

I was pleasantly surprised to find that, for me, gestures are the next best thing to having a slide or image as a visual memory cue. Deciding ahead of time what gestures to use was partially motivated by a workshop I attended on “The Performing Art of Science Presentation” by Nancy Houfek at the recent AAS meeting. I also appreciated the 30-second grace period, because it helped me be deliberate about my pacing and emphases. I was less likely to panic or speed up if I thought I was running behind.

Say… how is the whole I-work-for-LSST-at-UW-now-and-mostly-live-in-Seattle thing going? Very well, thank you! I only wish I could say the same for my country.

Without further ado, I present an approximate transcript of my #SciTalkNW three-minute talk. (I actually gave this talk twice: once in the initial round, and again in the final round, after some feedback from peers and experts.) When the conference organizers make a video available, I will update this post, and you can be amused at how my memory and the video differ.
UPDATE April 2017: link to my video, link to all the finalists’ videos

What’s your favorite picture of space? Maybe you think of one of those gorgeous Hubble pictures, like the Carina Nebula or the Pillars of Creation. Or maybe you have a memory of going outside at night, far from city lights, and looking up to see stars stretched across the sky.

All of these images have one thing in common: they’re static snapshots. They capture a single moment in time. But most things in space are dynamic and moving! While astronomers can learn a lot about our Universe from images like these, what we really need is a movie.

This is why a team of international scientists are building the Large Synoptic Survey Telescope, or LSST. It’s under construction right now on the top of a mountain in Chile. When completed, this telescope will have a main mirror that’s eight and a half meters across—that’s like 27 feet—and the largest camera ever built, the size of a small car. Inside the camera will be a detector with 3.2 gigapixels. That’s like several hundred iPhones in every snapshot.

When LSST comes online in 2022, it will begin mapping the entire southern sky. Every three nights, it will take one all-sky image. Then, over the course of a decade, it will stitch them together into the highest resolution movie of the night sky ever made. And, it’ll be in full color, because LSST will use six different color filters!

LSST is going to revolutionize pretty much every area of astrophysics. Everything from finding asteroids moving in our own Solar System, to observing stars explode as supernovae in distant galaxies.

But to do this, we recognize that the software is at least as important as the science. My team at the University of Washington is writing software to process the images that come from the LSST in real time. We’re talking 15 terabytes of data every night—that’s more than you can fit on your computer’s hard drive. And we have to process every image within 60 seconds of the shutter closing. Our software will take new images from the telescope, compare them to older images, and find anything that has changed. Those changes will then be broadcast in a public alert stream so that scientists can filter and search to find the targets they’re most interested in. All of our work is open and public, because we want scientists and folks like you to be able to use our tools.

So, in 2022, the movie begins! I am incredibly excited to share the ever-changing, dynamic cosmos with you. We’re going to find new kinds of variable and moving sources we didn’t even know to look for! Coming soon to a night sky near you: everyone’s new favorite space picture. LSST—it’s actually a movie.

Color is Weird

Yesterday on twitter, I ran across a perplexing image: yellow and magenta in a pair of windows that appeared to reflect blue and green, respectively, onto the sidewalk when illuminated by white light from the Sun.

What is going on?! I decided to put on my “I’m-an-astronomer-who-understands-light” cap and see if I could work it out. The rather circuitous tweet stream begins here, in which I made several errors: I tried to explain a complicated thing before I was fully awake, my brain kept switching key concepts like “absorb” vs. “reflect” and adding vs. subtracting colors of light, and I made a couple assumptions without explicitly stating them (spoiler: they turned out to be incorrect!).

Illustration of how colors of light add together. Source: Wikimedia commons

After much discussion on twitter, I concluded the paper posters in the window were reflecting their true colors (yellow and magenta) in all directions and leaving only their complementary light colors (blue and green) to reflect directly on the sidewalk. If you’re an astronomer, you might recognize this as analogous to Kirchhoff’s laws of spectroscopy: a nebula viewed from most lines of sight shows emission lines, but when it’s viewed in front of a bright object instead, you see absorption lines.

Yeah, that was wrong.

I took a closer look at the photo later that day, and realized the rectangles in the window were not posters at all, but looked more like transparent cellophane! That made things easier, I postulated:

Wrong again, though perhaps a bit closer.

The real explanation appeared today, when the original photographer returned to collect more data.




Trust me, you definitely want to play all those short videos (no sound required). The viewing angle changes everything! THAT’S SO COOL! Have you ever wondered why the cry of the scientist is “more data!”? It turns out that viewing something from more than one perspective can be very instructive, or should I say… illuminating? It’s enough to make this astronomer wish we had a way to fly halfway across the galaxy with a fleet of telescopes. Alas, space is way too big for that.

So there you have it: a learning experience, a more nuanced understanding of color, and a scientific quest all rolled into a handful of tweets.

Black Lives Matter

Together with colleagues from Astrobites, I am sharing a statement which appeared first on the Astronomy in Color blog and later on the Women in Astronomy blog. I have appended further thoughts inspired by the writings of Sarah Tuttle, Abigail Stevens, and Startorialist. Thank you all.

The recent extrajudicial killings of two Black men, Alton Sterling and Philando Castile, by the police have shocked, disturbed, and frightened many of us today. We express our unequivocal repulsion to these acts, which are just one manifestation of the underlying systemic racism in our country. These events affect our community directly. Many Black astronomers in this country, especially those in junior positions, are suffering at this moment. We encourage all of you to be mindful as you reach out to our fellow Black astronomers, and be present with them during these difficult times. The undersigned reaffirm our commitment to ensure the inclusion, support, and safety of every Black person in astronomy. Black lives matter!

To our present and future Black colleagues: your lives matter, and your contributions to science matter, too. We affirm that science does not happen in a societal vacuum. Science is done by human beings. We recognize that many forms of systemic racism take a real toll on you, and we know we cannot ignore this if we are serious about fostering an inclusive, equitable, and productive scientific community.

To everyone else: we need to stand in solidarity with our minoritized peers and colleagues, and with our Black colleagues in particular. The astronomical community is much more willing to discuss sexism than racism, and that is wrong. We live in a world where the inherent value of Black lives needs to be continually restated. White supremacy is what enables these extrajudicial murders by the police. White supremacy is what twists reality to tell you that Black Lives Matter is “political” and that science has no business acknowledging these atrocities. We disagree; inaction is not acceptable. There is humanity and there is racism. We hope you will join us in choosing humanity.

Dr. Meredith L. Rawls
Leonardo dos Santos
Ingrid Pelisoli
Kelly Malone
Evan Schneider
David Wilson
Susanna Kohler
Dr. Courtney D. Dressing

The above signatories are members of the Astrobites Collaboration ( This statement reflects our own personal views, and is not an official statement by Astrobites.

How to Make an Award-Winning Scientific Poster

  1. Decide with one month to spare that you will attend an overseas conference and frantically make travel arrangements.
  2. Email the incredibly responsive conference organizers because you’re not sure if you can give a talk or if you need to present a poster instead.
  3. Make a poster so great that you win the poster competition and get to give a last-minute talk the next morning as a result.

So that happened. You can watch my talk here.

The Cool Stars 19 conference was outstanding for many reasons, and winning the postdoc(!) poster competition was just one of them. Of course, the ability to make a good poster did not appear in my head out of nowhere! One set of great guidelines is here, and AstroBetter has compiled many handy resources about conference presentations (including posters) too.


Rather than rehash everything that has already been said about making effective posters (you did click on the links above, right?), here is an overview of how I approach poster design together with some tips to make your poster visually compelling.

  • Re-read the abstract you submitted to the conference weeks ago. Is it overly ambitious? Totally off-base? No matter. Your poster is an opportunity to communicate what you’ve done as of TODAY. Hundreds of people will glance at your poster, but only a few will skim your abstract.
  • With the above in mind, copy just the title and author list from your abstract submission (or craft a condensed version if necessary) and forget about the rest of it. Do not copy and paste your abstract anywhere. You will be staring at a giant blank canvas; it will be tempting. Just say no.
  • Use whatever software you are most comfortable with to make your poster. This could be Illustrator, Keynote, Powerpoint, Word, whatever. Does your software let you make a large page size, insert text boxes, images, and shapes, adjust fonts and colors, and precisely drag stuff around? Yes? Good.
  • Follow the conference’s rules for poster size. Sometimes you have a choice between portrait and landscape, and sometimes you don’t. You can make a good poster in virtually any aspect ratio, so pick something within the limit and stick with it. (US-based pro tip: 36 x 48″ is a standard size at FedEx Office and very similar to A0; having one dimension be 36″ also makes printing on fabric easier.)
  • Boil your message down to two main points, and be able to say each point in one tweetable sentence or less. Then divide your poster into three chunks: the first portion is reserved for big-picture motivation and context, and each of your main points gets another third. Use distilled versions of these points as headers for each chunk instead of meaningless words like “Introduction” and “Conclusions.”
  • The focus of each chunk must be figures. Let the figures speak for themselves. For example, you do not need to write “y generally increases with x over the full range of the dataset.” Instead, use clear axis labels that communicate why the correlation is important.
  • Write bullets and single-sentence captions, not paragraphs. Write only the most essential words to explain each figure, and no more. Notice there are no end-of-sentence periods on my poster, because each thought stands alone.
  • Avoid acronyms and jargon. Yes, knowing your audience is critical, but mostly, your audience is tired. Write what you mean, not what your sub-discipline’s jargon-and-acronym-machine expects you to say. If you must use acronyms, define them near the very start of your poster’s first chunk.
  • There is no ultimate poster font size law… but yours is too small because you’re trying to cram in too many words! My default was 52 pt (with some figure labels necessarily a bit smaller). Sans-serif fonts are easier to read than serif fonts.
  • Pick a simple, colorblind-friendly color scheme and stick with it. This means your plots, your text, and anything that goes on your poster should ideally coordinate. If you’re not sure what to choose, consider the colors in the figures you plan to include, and/or consider the color palette for the conference itself. Dark text on a light background is easier to read than the opposite.
  • Don’t be afraid to overhaul your figures. Crop out extraneous axes and tiny labels. Make custom legends. Annotate plots to drive home key messages. Present one illustrative example instead of seventeen nearly-identical panels.
  • Advertise your papers, and give credit where credit is due. Essentially everything on my poster is from my own work or my credited coauthors’ work, so there are very few formal citations. If you borrow any plots or images, be sure to cite the original source. However, a poster is not a literature review; if people are truly interested in your full set of citations, they can read your papers.
  • Take your time and be picky. Ensure elements line up within and between chunks, use the exact same colors and fonts throughout, and get several sets of eyes to proofread.

Remember: the whole reason you travel to conferences is to talk to people about your research. Sometimes you will be standing near your poster and sometimes not. Do you know what I did with all the words I wanted to put on my poster but didn’t? I used them in conversations, and they appear or will appear in papers. So yes, your poster must stand alone, but it shouldn’t have to tell the full story.

Finally, consider how you usually feel during a conference. Mentally sharp? Plenty of free time? Excited to carefully read each poster twice? Of course not. Everyone is exhausted and overwhelmed. That’s really what these tips are dancing around. Could your sleep-deprived officemate distill the essence of your poster after staring at it for 20 seconds? And do those 20 seconds make them care about your results? If not, you still have some work to do.

Dr. Rawls

My PhD defense took place in Las Cruces on April 8, and was successful! If you’re interested, you can watch my presentation and/or view my slides. However, please be aware the intended audience for this talk is fellow astronomers, not the general public.


I’ve spent the last week or so revising my dissertation, and I’m happy to report it passed the graduate school’s format review today. Once the final copies are printed (yes, multiple copies; yes, printed) and accepted, I will add it to the Astronomy Thesis Collection online and write a post summarizing the main results. I’ll be back in New Mexico in May to celebrate graduation with my family, and I intend to consume even more burritos before embarking on a road trip north.


On Writing a Thesis

If you spend any time around graduate students, you know the culmination of years of work toward a degree ultimately comes down to pouring the essence of that work into a giant written document very few will ever read: a thesis. Also known as a dissertation. (Due to my US-centric perspective, I treat the two as synonyms in this post.)

As it happens, I finished a full draft of my thesis yesterday. It has been a stressful, exhausting, anxiety-riddled few… weeks? months? Yeah. The “fun” isn’t over yet because there are certainly revisions in my future, not to mention the actual thesis defense, which will consist of a public talk followed by an indefinite period of conversation/questions/snake fights with my committee behind closed doors.

So that’ll be great.

But my goal today is to give future-thesis-writers a window into what my process looks like, and share the tools I used to make it slightly less painful than it could have been.

My thesis contains five chapters and three appendices in about 200 pages and roughly 25,000 words. (The word count is imprecise and rounded down because a thesis has lots of words that aren’t exactly part of the main text.) As I understand it, this is a reasonably typical length for astronomy, but I honestly don’t care, because I think I said everything I needed to say.

I have three pieces of unsolicited advice, which boil down to: know how you work, get tools you’ll use, and what I’ll call “think globally, write locally.” Let’s go.

Know how you work

Maybe you’re one of those people who likes to wake up early, gets important work done before the rest of the world is awake, has completed all your thesis research well in advance of when you’d like to defend, and has published four papers along the way. In that case, I say congratu-effing-lations, you have this in the bag.

For the rest of us, it’s time to take stock of how you work. Think about the last time you were really “in the zone” and got a lot of work done solo. Where were you? What was the environment like? What time of day was it? Did you have a certain beverage, view, or music at hand? Figure out what works best for you and structure your life around it. Maybe that means you need to unplug the internet, build a playlist, budget for daily coffeeshop purchases, work in pomodoros, disable email notifications, or embrace the popcorn workstation. Maybe it means you need to block out writing hours on your calendar, get a transit pass, find a standing desk, set weekly deadlines, or pull all-nighters every Tuesday. It doesn’t have to make logical sense and it doesn’t have to be a lifelong commitment; it just has to work for you for now.

If you’re having a hard time remembering the last time you felt highly productive working alone, or the specific circumstances, don’t despair. It’s never too late to try new productivity techniques. We’re all making this up as we go!

Get tools you’ll use

Writing a thesis is more than just opening a blank document and dumping your brain into it. There’s formatting and references and figures and tables and… so many pieces that somehow have to come together. Thankfully you are not the first person in the history of humanity to tackle these problems, and lots of tools exist to help. Good tools are easy to use and lighten your cognitive load so you can focus on the content of your thesis rather than the mechanics of writing it. But not every tool works for everyone, and sometimes you have to be patient with yourself and your computer while you try and discard one after another. After much trial and error, here are some of my favorites.

OmniFocus: The powerful to-do list app that basically changed my life. This is a place to write down action items for everything in your life, from errands to work to any random task or idea you need to get out of your brain. The degree to which I use OmniFocus to its full potential varies, but whenever I need to get something done I take the time to break it up into small, manageable pieces here. You can use it to set deadlines, start-later deferral dates, color categorizations, location- or person-based contexts, and so much more. OmniFocus is not free, it is only for Mac/iOS, and it syncs seamlessly between them. If you are thinking of trying just one of the tools listed here, it is the one I recommend most highly.

TeXShop, ShareLaTeX, and a LaTeX class file: If you want to write a thesis, you’re probably going to need some LaTeX. My editor of choice is TeXShop, which is free and lets you place writing (editor) and viewing (PDF) windows side by side. If installing LaTeX gives you trouble, I recommend ShareLaTeX, which is also free, works in any browser, and syncs with Dropbox (see below). You’ll also need a class file with various packages to tell LaTeX how you want your thesis formatted. Many departments and universities have official or unofficial class files that adhere to formatting guidelines. Ask around to see what older students or recent graduates from your department have used. In my case, NMSU graduate Jeff Coughlin created aastex-thesis (based on AASTeX v5) and a set of well-documented sample files that compile into a pretend thesis—about exowhales, no less!

Dropbox: You probably don’t back up your work as often as you should, and even if you do, it’s probably not every time you hit “save.” I initially uploaded my thesis files to ShareLaTeX, linked that to Dropbox, and then did most of my writing in TexShop. So long as I was online, the latest versions of all my thesis files were automatically synced with the cloud. This offered peace of mind, because if my computer spontaneously self-destructed, I could have continued working with ShareLaTeX on any computer with internet access.

TextWrangler: My go-to text editor. You can use alt/option-click to select a rectangular block of text (a column), it has brilliant find-and-replace, and it lets you remotely edit files over ssh. I use this for everything, including python programming, formatting LaTeX tables, and keeping a BibTeX bibliography file up to date. TextWrangler is free and for Mac only.

Papers: The absolute last thing I want to actively think about is how to cite a paper or format my bibliography. BibTeX handles some of this, but it can’t help me find the paper I’m looking for or open several in tabs for me to continually reference. Papers lets you save PDFs in a special folder, automatically organizes that folder and imports information about that paper, and makes it easy to copy a BibTeX record into your bibliography file. From there, you can customize a natbib keyword, run a series of LaTeX-BibTeX-LaTeX-LaTeX commands in TeXShop, and carry on writing. Papers also syncs between devices (Mac/Windows/iOS) so you can read papers on the go. It’s not free, but they offer student pricing and it is well worth the investment.

SnagIt: This is just a fancy screenshot program. I use it to grab a figure from a paper, save it in the “figures” subdirectory of my main thesis directory, and add it to my thesis. It’s not free, but there are many other perfectly good screenshot options out there.

Evernote: My research notebook. My workflow is essentially paperless, so anything I need to jot down goes here. I write a brief summary of what I did each day for my own personal reference. Quick calculations, the location of important files, and notes taken during meetings all land in Evernote. It’s free and syncs between all my devices which makes it a handy reference during meetings and conferences.

RescueTime: A neat little free app that runs in the background on my computer and tracks how much time I spend using different applications. It keeps you honest and lets you compare hours spent on different tasks from week to week.

focus@will: Various types of music and ambient sounds that help get you in the flow of working. I use this when I just can’t concentrate and/or when I want music but don’t want to spend time deciding what to listen to. It’s a subscription service with a free trial period. [post edited to add this one]

Slack: Did I mention I’ve been finishing my PhD remotely over the last year? This means my collaborators are never “just down the hall,” and Slack bridges that gap for free. I’ve become at least as good of a communicator from afar than I ever was when I could theoretically walk to a colleague’s office. For example, during a virtual meeting, everyone can easily share plots and other files in real time.

“Think globally, write locally”

One of the most challenging parts of a thesis is figuring out just how to pitch your epic, unprecedented contribution to the field. There’s no getting around it: this is important, and part of the game is convincing others your results matter. But if you don’t have it figured out yet, there’s no reason you can’t start writing your thesis anyway. I essentially arrived at my conclusions as I was writing, for two reasons: the final numbers pertaining to my stars weren’t ready until days before my draft was due, and the process of writing about those numbers helped me clarify the story they could tell.

I can’t work if things aren’t organized, so the first thing I did after I had a set of mostly-empty LaTeX files in place was come up with chapter and section titles. I decided, quite arbitrarily, that I was going to have four chapters: Introduction, That Paper I Just Published, and Applying Stuff I Did In That Paper To Similar Situations (split into two logical halves), and three appendices. Then I created sections, and subsections, and even a few sub-subsections. Once all this was written down, I had a clearer idea of what my thesis looked like globally. Then I could pick a smaller “local” section I was ready to work on and get a finite piece of thesis done in one writing session.

That’s not to say the chapters and sections couldn’t change! They most certainly could, and did; for instance, at the eleventh hour, it was decided I would write a fifth chapter entitled Larger Context And Summary Of This Entire Damn Thing. More or less. But by that point, it was clear I had some things left to say which did not fit in the other four chapters, and adjusting course made sense.

With tools in place to handle formatting, citations, figures and tables, colleague communication, a to-do list with bite-sized pieces, and an outline as a jumping-off point, all that was left was the writing. I know enough about how I work to block off large chunks of time in the afternoon and evening during the last few weeks, which culminated in one final writing push from 10pm-5am on Sunday night. It sucked, but it worked. At least, I think it did. My committee will have the final say on that in the next couple of weeks.

Not my favorite way to spend Easter weekend, but I think the bunny had it worse.