Archive | May 2010

A brief history of clumpy galaxies

The vast majority of galaxies we see around us today can be grouped into just a few categories of visual appearance, or morphology. There are spirals and lenticulars (barred and not), ellipticals and irregulars. These are described in this recent post and will be looked at more closely in the Galaxies 101 series. Things get a bit more complicated when one goes to faint and small “dwarf” galaxies, but we won’t go into that here. There are also a small fraction of galaxies that are in the process of merging, often creating unusual and spectacular morphologies, but again they will have to wait for a future post.

Tadpole galaxies

Example tadpole galaxies in the Hubble Ultra Deep Field.

Studying the morphologies of galaxies was quickly recognised as an interesting thing to do, as it gives us lots of clues as to how galaxies originally formed and how they have interacted with one another and their surroundings over the history of the Universe. However, because of the blurring effect of the atmosphere, and the fact that galaxies, like everything else, appear smaller the further away they are, for a long time it was not possible to see the morphologies of distant galaxies. With big telescopes, though, we could still determine their brightnesses, colours and numbers. From these measurements we knew that far-away galaxies were generally different from those nearby. Remember that the finite speed of light means that we see distant galaxies as they were in the past, when the Universe was younger. This useful fact means that we can directly see how the galaxy population has evolved just by looking further and further away. But while our telescopes were stuck on the ground we couldn’t see what galaxies in the early Universe actually look like.

Clumpy spiral galaxies

Example clumpy spiral galaxies in GOODS imaging, from Elmegreen et al. 2009. Each panel includes a bar of length 2 kpc, the object’s redshift and COMBO-17 ID number.

The Hubble Space Telescope (HST), together with its camera WFPC2, solved the problem. Free from the atmosphere, it could see details ten times finer than ground-based telescopes. Finally we could see distant galaxies clearly enough to study their morphology. To demonstrate HST’s power, some of the first HST images were taken by staring at the same patch of the sky for a very long time, producing very deep images. Studies of these images of the distant Universe (e.g., by Cowie, Hu & Songaila in 1995 and van den Bergh and colloborators in 1996) revealed that the galaxy types seen nearby were still present, but generally become “messier” the further back in time one looks. Furthermore, there appeared to be types of distant galaxies that we do not see today. Many of these galaxies comprise knots or clumps. In particular, many galaxies were found with an appearance of several clumps arranged in a line, and were named “chain galaxies”. Galaxies with two clumps were simply named “doubles”. There were also galaxies with the appearance of one clump with a tail, appropriately named “tadpole galaxies”!

Example clumpy galaxies

Example clumpy galaxies, details as above.

For the next few years, most studies of galaxy morphology with the HST concentrated on galaxies at intermediate distances, where HST provided detail impossible to obtain from the ground, without requiring very long exposure times. Galaxy morphologies are becoming messier at these times, but the clumpy galaxies seen in the deepest surveys were much more distant. However, the field of distant galaxy morphology had a further renaissance with the replacement of the WFPC2 camera with the Advanced Camera for Surveys (ACS). This enabled even deeper, clearer images to be obtained more quickly. Studies of these images (e.g., particularly by the Elmegreens and collaborators) find that clumpy galaxies become extremely common in the early universe. The extra depth of these data has revealed a population of clumpy galaxies that do not appear as chains, but rather more circular groups of clumps. These have been named “clump clusters”. While clump clusters share similarities with modern-day irregular galaxies there are a few important differences. Clump clusters are generally much more massive, and today’s irregulars would look irregular no matter which direction they are viewed from. The similarilty between clump clusters and chain galaxies implies that they are the same kind of object, simply viewed from different directions. This means that the clumps must be irregularly distributed in fairly thin disks, which appear as chains when viewed edge-on.

Clumpy embedded galaxies

Examples of clumps in an underlying red galaxy, details as above.

Further studies of clumpy galaxies confirm that they are very young galaxies with lots of star formation occuring in the massive clumps, which may be embedded within a slightly older, smoother distribution of stars. Their prevalence means they are likely to be an early phase in the development of most, if not all, galaxies.

As I mentioned in my previous post, for Galaxy Zoo: Hubble we added a series of questions in order to find out about the appearance of clumpy galaxies. This will provide us with a catalogue of their properties that is larger and more consistent than any before. By analysing this data we hope to learn much more about these galaxies. For example, there appears to be a rough developmental sequence from asymmetric clumpy galaxies, to symmetric clumpy galaxies, to clumpy galaxies dominated by a bright, central clump, and finally to spiral galaxies. Other clumpy galaxies may merge together to form ellipticals. By comparing the numbers and properties of these different types of galaxies we will be able to confirm or refute this picture, and better understand the origins of the galaxy population.

Classification tree tweaks

Some of you may have noticed that on Thursday we made a couple of small changes to the flow of questions that are asked for each object in Galaxy Zoo: Hubble. Both of these changes relate to the set of additional questions which we introduced during the switch from Galaxy Zoo 2 to Galaxy Zoo: Hubble. As you will have certainly noticed, the new Hubble Space Telescope images contain many more galaxies with a clumpy appearance. This type of galaxy was very rare in the Sloan Digital Sky Survey images and doesn’t really fit into the classification tree we used for Galaxy Zoo 2. To obtain useful classifications for these objects in Galaxy Zoo: Hubble we therefore decided to add another branch of questions to the “classification tree”.

Clumpy questionsDuring the first month or so of Galaxy Zoo: Hubble we have received a great deal of very useful feedback, particularly on the forum. In particular, two features of the new classification tree appeared to cause a fair bit of consternation amongst some of the Zooites. After considering your comments, and much deliberation, we decided to make a few changes.

Both points of contention related to the question asked after an answer had been clicked for ‘How many clumps are there?’. If the answer was anything except ‘one’, then we then asked ‘Do the clumps appear in a straight line, a chain, a cluster or a spiral pattern?’. Now, that’s a hard enough question to answer when there is only three clumps, but doesn’t make much sense at all when there are just two. We were trying to keep things simple but, to be perfectly honest, this wasn’t very sensible on our part. We have now changed the tree so that if the answer given is ‘two’, the question about how they are arranged is skipped.

The second issue was more interesting, because the frustration it caused told us something about the appearance of the clumpy galaxies which we hadn’t properly appreciated when planning the questions. New astrophysical insight before we’ve even collected enough clicks to start analysing! If the answer to ‘How many clumps are there?’ was ‘one’, the classification tree went back to the branch for ‘Smooth’ galaxies and asked ‘How rounded is it?’. Our thinking here was that a galaxy that was mostly just one clump would probably be an elliptical or maybe a bulge within a smooth disk galaxy.

It seems we both underestimated the discriminatory power of the Galaxy Zoo participants and how clearly different clumpy galaxies are from other types, even when there is only one clump. After having seen a few clumpy galaxies, it seems that many Zooites come to recognise that there are subtle features that set them apart from other types of galaxies. This suggests that single-clump galaxies really are a clearly different type of galaxy to the ellipticals and disks that are more common nearby. For single clump galaxies we now carry on asking the usual clumpy galaxy questions, skipping those that don’t make sense for only one clump.

Don’t worry – all your previous classifications of one (and two) clump galaxies are still safely stored away and will be very useful in helping us catalogue the subtle differences between the appearances of all these objects. Thank you, and keep clicking!

Voorwerp Web-Comic: Authors meeting at CONvergence

It came from the SDSS: The Voorwerp

It came from the SDSS: The Voorwerp

Have you ever looked at the Voorwerp and said to yourself, “Doesn’t that look like the Swamp Thing?” Or maybe you’ve seen Kermit the Frog dancing, or a maybe you see foliage run amok. There is just something about the Voorwerp that make me, for one, want to anthropomorphize it as a monster, and I’m betting some of you have had the same moment of Pareidolia.

The neat thing about the Voorwerp is it not only looks like the character from a bad monster movie, but it is a real-life monster of a problem that has played a starring role in an intellectual adventure. While astronomy doesn’t normally get turned into summer block buster movies, this story just might make it with a rating of “S: Judged appropriate for people who contribute to science in their spare time.”

Image with me – you go into a movie theatre and hear booming from the speakers: “It came on the 13th; Monday the 13th. And one woman dared to ask ‘What is that stuff?'” Suddenly the camera zooms in on the Voorwerp. Then this imaginary movie trailer has us cutting between action adventure shots of astronomers racing for telescopes (you see a car racing across the desert with domes in the distance), the Swift space telescope  repointing, and Zoo Keepers conferring in solemn tones as they gather around a computer. Bill Keel (played by Martin Sheen?) asks, “Can we get Hubble time?” and someone played by the Hollywood hunk of your choice responds in an overly dramatic tone, “I don’t know, but we have to try – I want answers – and we can handle the truth.”

Ok, so maybe the idea is pure cheese, and no Hollywood director (or college film major) is likely to shoot this flick, but there is still a story here that is worth sharing with the world.

And the STScI agrees with us. They’ve funded the creation of a digitized comic book (a web comic) to tell the story of Hanny’s discovery of the Voorwerp and the scientific adventure all of us have gone on as the truth has been sought in all sorts of wavelengths using a myriad of telescopes.

This comic is being written under the guidance of Kelly McCullough (author of the Ravirn series) by a team of volunteer writers at the CONvergence Con outside of Minneapolis, Minnesota, USA. The writers will work in close collaboration with Bill Keel and many other Zoo Keepers to make sure they get the story completely right.

Want to watch? Want to hang out with Zoo Keepers (list of attendees to come) at a cool event? Then join us in Bloomington, Minnesota, July 1-4, 2010. The event does cost money, unfortunately, and you have to register (My turn to bring the cookies). The cost of registration goes up May 15, so if you’re interested, please register ASAP for lowest prices.

We’ll be releasing the comic at Dragon*Con in the fall. We’d love it if you’d consider coming and being part of the celebration.

We’re going to work to keep you informed about everything that is going on. You can follow along at http://hannysvoorwerp.zooniverse.org, and in the webcomic thread on the forums.

Types of Galaxies

Last time I talked about the Great Debate of 1920, and about Edwin Hubble’s discovery that Galaxies lie beyond the Milky Way. The 1920s changed over view of the Universe – they made it much larger! This time I’m going to quickly outline the basic types of galaxies and the kind of sizes and distances we are dealing with.

Galaxies are usually grouped by their appearance. You may be familiar with spiral galaxies, for example. In fact there are two types of spiral galaxy: those with bars through their middle, and those without. You also have elliptical galaxies, which are basically big blobs of stars. Finally there are irregular galaxies, i.e. galaxies that don’t seem to be one shape or another really. There are examples of each of these types shown below – taken from the Galaxy Zoo data, of course!

spirals

Spirals

barredspirals

Barred Spirals

ellipticals

Ellipticals

irregulars

Irregulars

The different shapes of galaxies tell us something about their properties, and we’ll deal with each type of galaxy in the next few blog posts. For now I thought I’d end with another of Hubble’s ideas. When he saw these different types of galaxies he tried to understand the different shapes as an overall evolution. He thought that elliptical galaxies might evolve into spirals as time went by. The Hubble ‘tuning fork’ diagram is shown below.

HubbleTuningFork2w

Hubble called the elliptical galaxies ‘early’ galaxies and the spirals ‘late’ galaxies. Galaxies do not move left across the diagram as they evolve, but still the diagram is a nice way to visualise the varying shapes of galaxies relative to one another. Understanding the shapes – or morphologies – of galaxies are a huge part of the motivation behind the Galaxy Zoo project. you can learn more about it on our science pages.

[UPDATE: This post has been modified from its original form to correct some errors on my part.]

Dust in the Zoo – chapters opening, continuing, and closing

Anna Manning and I are back at Kitt Peak, using the 3.5m WIYN telescope for
more observations of overlapping-galaxy systems from the Galaxy Zoo sample.
This trip started with an unexpected dust encounter. Indulging my fascination with some of the technological excesses of the Cold War, I dragged Anna (and my mother-in-law as well) to Tucson’s Pima Air and Space Museum. I particularly wanted to see their newly-restored B-36 aircraft, one of only 4 of these vintage giants left. The wind had been high already, but really whipped up and caught us in a dust storm (with added rain so it was like tiny mud droplets stinging the skin). Anna pointed out the irony, especially since I had announced on Twitter that “dust will be revealed, in detail”. Maybe next time it is I who should be more detailed.
Read More…

She's an Astronomer: Meg Urry

Prof. Meg Urry is a professor of Physics and Chair of the Physics Department at Yale University. Her research concerns supermassive black holes: how and when they grew, how they inject power to their surroundings, and how they interact with their host galaxies.

Meg was born in the Midwest region of the U.S. and moved to the Boston area as a teenager. After high school she went to college nearby, at Tufts University, where she double majored in mathematics and physics.

After Tufts, Meg went to graduate school in Physics at the Johns Hopkins University in Baltimore, where she got her PhD for research on blazars at NASA’s Goddard Space Flight Center near Washington. Her JHU advisor was Art Davidsen, who during this time proposed the Space Telescope Science Institute (STScI) as the observatory to run the Hubble Space Telescope (HST) for NASA.  While at Goddard she met her future husband, Andy Szymkowiak, also a graduate student in Physics. (Interesting fact: 2/3 of married women in physics are married to men in physics or closely related fields.)

Meg then took a postdoctoral position back in Boston, at the Massachusetts Institute of Technology (MIT), in Claude Canizares’s group.

After MIT, Meg moved back to Baltimore for a second postdoctoral position, at STScI, now in a new building, with 200 employees. (When she left JHU 3 years earlier, STScI had only a handful of employees housed in the JHU Physics building.) She also married Andy Szymkowiak, whom she met at Goddard. Three years after returning to STScI, she became an Assistant Astronomer on the tenure track there, rising through the ranks to tenure and then full Astronomer. She had her two daughters, Amelia and Sophia, while an Assistant Astronomer, after which (too late to benefit her own family) she agitated for better parental leave policies, onsite daycare, and a lactation room. She was the prime organizer, with Laura Danly, of the first Women in Astronomy meeting, held at STScI in 1992, which gave rise to the Baltimore Charter.  For her day job, she managed the group of research assistants who helped staff and visiting scientists use Hubble and later ran the Science Program Selection Office, which determines what observations HST will do. Meg really enjoyed the proposal solicitation and review because it involved hundreds of scientists from around the world, engaged for a few intense weeks in reviewing and ranking exciting new ideas for Hubble science investigations.

But Meg was really born to teach. She loved being a Teaching Assistant in graduate school and a Recitation Instructors at MIT. She even took a 6-week detour from graduate school to teach physics to Air Force personnel at Ramstein Air Force base in Germany. Her students were talented non-commissioned officers who needed the Physics plus lab credit to qualify for Officer Candidate School, and she loved teaching them physics: lecture every morning, labs every afternoon, and help sessions every evening. Physics, physics, physics – and all of it fun.

In 2001, Meg moved to Yale University, roughly midway between Boston and Baltimore, thus ending her oscillations along the East Coast. There she directed the newly created Yale Center for Astronomy and Astrophysics, establishing a prize postdoctoral fellowship program, co-leading a Key Project in the Yale-Chile collaboration, and getting Yale involved in the Keck telescope consortium. She taught concept-based Introductory Physics, introducing “clickers” and peer-to-peer learning, and she created a new astrophysics course to introduce science majors to active frontiers in the field, namely, exoplanets, black holes, and the accelerating Universe. She developed a lively research group, with graduate students Jonghak Woo, Ezequiel Treister, Jeff van Duyne, Brooke Simmons, Shanil Virani, and Carie Cardamone (a blogger on the Galaxy Zoo forum); postdoctoral associates Eleni Chatzichristou, Yasunobu Uchiyama, Kevin Schawinski and Erin Bonning; and numerous wonderful undergraduates. In 2007, Meg was appointed Chair of the Physics Department, and was appointed to a second term this year. Her daughter Amelia is now a freshman at Yale and her daughter Sophia is a junior at Hopkins high school in New Haven.

megurrykids

The most wonderful girls in the world (left portrait by Jada Rowland, 2001; right photo from vacation in Paris, 2008)


  • How did you first hear about Galaxy Zoo?

In 2008 I hired a new postdoc, Kevin Schawinski, who co-founded Galaxy Zoo with Chris Lintott. When Kevin told me about the concept and what had already been accomplished, I was deeply impressed. It is a brilliant idea and the results are mind-boggling. Galaxy Zoo has greatly improved the quality of galaxy classification and has made possible investigations that could never have been done previously.

  • What has been your main involvement in the Galaxy Zoo project?

In the past two years my group has used Galaxy Zoo results in several recent studies, led by Kevin Schawinski (now an Einstein Fellow in my group) and Carie Cardamone (a graduate student finishing her thesis with me). We have published on Green Peas (Cardamone et al. 2009), the phasing of black hole growth and star formation in the host galaxy (Schawinski et al. 2009), and the dependence of black hole growth on host galaxy morphology (Schawinski et al. 2010a). None of these results would have been possible without Galaxy Zoo.  My favorite (because I still don’t understand the results) is the paper led by Kevin on the different modes of black hole growth in elliptical and spiral galaxies (Schawinski et al. 2010a). When Kevin suggested separating active galaxies (galaxies whose central supermassive black hole is actively accreting and thus producing lots of non-stellar light) by morphology, I frankly didn’t think the investigation would turn up anything interesting. Boy, was I wrong! We found that patterns of activity differ markedly in ellipticals and spirals, with high-mass black holes growing the latter and mostly low-mass black holes growing in the former. The trends in ellipticals may make sense if mergers are important in triggering AGN activity (see another paper from our group, Schawinski et al. 2010b, that uses Galaxy Zoo classifications of mergers ) but the results for spirals still have me puzzled. It’s a great, fun challenge to understand what’s going on.

  • How/when did you first get interested in Astronomy?

I came late to astronomy compared to many of my colleagues. As a high school student, I liked every field – English (19th and 20th century British and American writers especially, History (I remember writing several papers on the Civil War just for fun), Math (*loved* calculus! Why don’t they teach it earlier?), languages (I’ve studied Spanish, French, German and Italian), Chemistry (thanks to the marvelous Miss Helen Crawley) – well, you get the picture: I was a thoroughly undecided undergraduate. Then I took Physics as a freshman at Tufts and for the first time, felt both the challenge and reward of understanding some difficult material. The summer after my junior year at Tufts, I was lucky enough to get a research internship with Richard Porcas at the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia. (My roommate for the summer was Melissa McGrath, then an undergraduate at Mount Holyoke and later a colleague and planetary astronomy at STScI. Melissa now heads the Science Division at NASA’s Marshall Space Flight Center.) Porcas taught me some astronomy (he was probably a bit horrified to realize I knew very little), especially radio astronomy, and he also introduced me to Monty Python. (That summer, the Queen visited the U.S. and passed through Charlottesville. Porcas, a Brit, made sure to catch the procession.)

One of my main jobs was to use the Palomar Sky Survey prints to find optical counterparts to radio sources from the Jodrell Bank high declination survey. I kept a notebook carefully describing the fields around each radio source. (Since the spatial resolution of the Jodrell Bank radio telescope was not as good as that on the PSS prints, there were sometimes more than one candidate counterpart, often offset from the nominal position.) Two memorable things happened as a result of that work: I saw the first gravitational lens, 0957+561; a reproduction of my neat handwriting noting “two blue stellar objects of equal magnitude about 5 arcseconds from the radio source” appears in a paper by Dennis Walsh in 1979, which recounted its discovery. Of course, I had no idea I was looking at a gravitational lens – I didn’t even know what they were at that point. But it was nice nonetheless to be a part of history. The second funny thing was that Porcas realized, halfway through the summer, that he could get an unbiased estimate of the false detection rate of optical counterparts if he fed me some random, meaningless positions. Sure enough, I started finding more and more supposed radio sources with no optical counterparts. (In reality, these were just blank-sky positions.) I can’t remember if I noticed the dramatic change in identification rate or if Richard finally confessed his secret scheme – at the time, I was a bit chagrined to be duped so easily, but now I see it as an excellent research protocol.

In any case, my summer at NRAO was what got me into astronomy. It was fun, the people were friendly (weekly volleyball games were a favorite, as was watching the Olympics with my new astronomer friends, and it was amazing to realize people earned a living doing something so interesting. After that experience, I was going to do astronomy and astrophysics if at all possible.

  • What (if any) do you think are the main barriers to women’s involvement in Astronomy or Physics or science generally?

It took me quite a while to accept that the playing field is not yet level for women in science. As an undergraduate and graduate student in an era when discrimination was supposedly over, women’s liberation was an established movement, and laws had been passed to chip away at discriminatory practices, I frankly didn’t expect any problems and I didn’t notice any. True, I was usually the only woman in my physics classes but at some level, I reveled in the distinction. (Even as a kid I had been motivated by the idea of being the “first woman,” as in first woman astronaut or first woman president. The first of those took place long after it should have, and we’re still waiting for the second.) But at first I didn’t detect any discrimination and I didn’t particularly feel the need to network with other women in science. When I see young women today with those attitudes, I find myself hoping that in their case, it will be true, by the time they are my age, that they have suffered no discrimination – it might happen, especially in Astronomy, which is more female-friendly than Physics. And I don’t think it’s a bad thing to be oblivious, as I was – it probably kept me from dissipating energy fighting the machine.

But it was inevitable I would take up “the cause.” As a postdoc, the lack of women started to bother me. Where were the other women who had gotten physics degrees? At MIT, I was the only female postdoc in space science, out of dozens. Meanwhile, people had been telling me for years that, as a woman, I would benefit (the implication was, unfairly) from affirmative action – I should have no trouble getting into grad school, getting a postdoc, getting a faculty position, whatever – because all the universities would be eager to hire women. When people say this today, as they often do, I have to laugh. I sure do wish it were true but 30 years in physics and astronomy have shown me, instead, the huge pile of female talent that goes wasted every year. Fewer women are sought after as speakers, assistant professors, prize winners, than men of comparable ability. I have seen talented women ignored, overlooked, and sometimes denigrated to the point where they abandon their dreams. It sounds harsh but I simply report what I have seen. Men, too, leave the profession, but the numbers don’t compare. The percentage of scientists who are women drops at every level, until there are too few women to make a statistically significant measurement.

Hmm, sorry, this has turned into a lecture. Didn’t mean to do that. So let me keep it simple: there is discrimination, and it is done by all of us, men and women both, quite unconsciously for the most part. There is a large body of research in the social science literature (which, unfortunately, natural scientists rarely read) documenting the natural tendency of all of us – people raised in a society where men dominate leadership roles in most fields – to undervalue women. I hope young women don’t experience what I did – and there’s a good chance they won’t – but every young woman or under-represented minority scientist should learn about this “unconscious bias” so that, should they ever find themselves getting discouraged or feeling inadequate as scientists, they will correct for the effect of a harmful environment and recognize their own considerable achievements and talents. Or just call me! I’ll be happy to try to reassure them. It’s probably not them, it’s that they are trying to do science in an environment that is unwittingly toxic.

  • Do you have any particular role models in Astronomy?

I have definitely had role models, although often I didn’t recognize it at the time.

My father was a Professor of Chemistry at Tufts University and my mother had been trained as a zoologist. They met at the Museum of Science and Industry in Chicago, where they were docents (my mother used to give presentations on the “invisible woman,” a transparent human form whose internal organs and systems were visible) and where both were students at the University of Chicago. Years after the decision to study science, I realized that living with two scientist parents, I couldn’t help but think like a scientist. Much as I enjoyed other subjects like English or History, the scholarship in those fields felt too arbitrary, whereas science has as its focus Nature, which is what it is. That is, scientists may form hypotheses about Nature but they cannot choose what to believe – they simply discover it from observation.

My thesis research was done as a member of the X-ray astronomy group at Goddard, where my de facto advisor was Richard Mushotzky, now at the University of Maryland. My first postdoc at MIT was in Claude Canizares’s group. Like my father, both Richard and Claude were important role model for how to be a professor, mentor students, and run a research group.

I have mentioned male role models (my dad, Mushotzky, Canizares) – they definitely taught me how to be a professor – but the women were probably more important just because there were so few. They taught me how to keep going: Marie Curie, Helen Crawley, Anne Kinney, Vera Rubin, Margaret Burbidge, Andrea Dupree, Martha Haynes.

  • What do you think is the most interesting astronomical question Galaxy Zoo will help to solve?

I don’t know. If it’s something I can imagine, it’s probably not very different from what we know/understand now. The most interesting question is probably something I can’t even think of. Take Hanny’s Voorwerp as an example: Galaxy Zoo volunteers found this, not professional astronomers. Who knows what you guys will come up with next? I can’t wait to see.


This post completes our She’s an Astronomer series on the Galaxy Zoo Blog run in support of the IYA2009 cornerstone project of the same name (She’s an Astronomer – we are listed on the She’s an Astronomer website in their Profiles.). In total we’ve interviewed 16 women involved in Galaxy Zoo – 8 zooites (or volunteers) and 8 researchers (or professional astronomers). All of the interviews were conducted in English, but we also posted native language translations for 4 of the particiants (Spanish, German and Dutch).

Here’s the full list of interviews:

Hope you’ve enjoyed it. I still plan to write some roundup posts summarizing the series if I can find time here in baby land!