In the most recent volume of Nature---a high-impact, highly selective general-science journal---there is the usual collection of cutting-edge research articles. There's an article about an ancient ice shell on Saturn's moon Titan. There's another about the genetic sequencing of yeast.
Planetary science and genetics are interesting, but one article in particular really stood out to this astronomer. Its title is An observational correlation between stellar brightness variations and surface gravity (Bastien, Stassun, Basri & Pepper 2013, Nature 500, pp. 427-430). The novel and impactful scientific result is an empirical link between the bulk photometric variability of stars to their surface gravity, a key stellar property previously only measurable from high-resolution spectroscopy or extremely difficult asteroseismic observations. Bastien and collaborators coin the term "flicker" to describe the root-mean-square variability of stellar brightness on 8-hour time scales. Stars with low surface gravity are bigger and "fluffier" and when convective bubbles in their interiors rise and hit their atmospheres, they oscillate with large amplitudes (large flicker). Thus, flicker and surface gravity are related (see figure below). If you can measure a star's flicker, you can measure it's surface gravity.
This finding has some important implications for my own research, and it's yet another groundbreaking result to come out of the NASA Kepler Mission. For an excellent review of the science, check out Chris Faesi's Astrobites article, or the associated Nature News & Views article by Christensen-Dalsgaard (behind a paywall).
Fabienne Bastien, is the first Black female astronomer to ever publish a first-author Nature article (Bolded word added per my correction on my previous claim that she was the first Black astronomer to do this. At least three Black men have done so.). This fact highlights a couple things, one somewhat negative and one positive. On the negative side, why the hell is this record being set in 2013 and not 1985?! It's a commentary on the sad state of diversity (or the lack thereof) in astronomy. As I've written before, it's my goal to see to it that we, as a community, quickly tuck these sorts of records away post haste and move into a future in which there are more than 0.5 Black astro Ph.D.s per year and more than 11 total black astronomy professors in a community of thousands.
|Fabienne Bastien, a stellar|
Black stellar astrophysicist!
Also encouraging is that Harvard astronomy admitted a black student into their graduate program this year---the first in ~30 years---and I am looking forward to mentoring him while he's here. Keep an eye on the Harvard astro program as I, and others, work to build a more diverse community and usher in a long awaited sea change in this field. It's my feeling that game-changers like Fabienne and Gibor Basri (her coauthor) are born each year in the Black community. We astronomers do a disservice to our science by not seeking them out, training them and welcoming them into our discipline. It behooves us all to increase inclusion so as to hasten our understanding of the Universe (more minds, more progress) and give back to the greater society, at whose pleasure we serve and study (Black folks fund the NSF and NASA, too).