Andrew Mann
@amann
Associate professor of Physics and Astronomy at UNC Chapel Hill studying young exoplanets and stars. Dad to one human and one cat. 🏳️🌈💗💜. Carrboro Citizen.
A while back, Elisabeth Newton visited and commissioned Isabel to do some for her students as well. I attached a few below. These are for Drs. Aylin Garcia Soto, Keighley Rockcliffe and Rayna Rampalli. 🔭🧪⭐🎨
As a graduation present, I give my PhD students posters based on their research. I have a few examples shown here (Dr. Pa Chia Thao and Dr. Reilly Milburn). These are done by PhD student and artist Isabel Lopez Murillo: analopezmurillo.github.io 🧪🔭⭐🎨
Last is the SOYSAUCE survey, PI Madyson Barber. Work on studying the alignment between planets and their host stars, focusing on <200 Myr systems (fast misalignment or primordial misalignments). So far, things look aligned. This was done as a twilight zone reference 🧪🔭⭐ #exoplanets
Next, Isabel Lopez Murillo's fantastic work on transiting timing variations in young planetary systems. Really solid design. You can tell she's also an artist. 🧪🔭⭐ #exoplanetshttps://analopezmurillo.github.io/
First up, old timey newspaper highlighting the discovery of the greater pleiades complex and the >1million-star catalog of rotation periods from TESS. 🧪🔭⭐ #exoplanets Work by Andy Boyle.
My OCD demands that TESS observe the final missing block as soon as possible. 🧪🔭⭐
I should note that the description REQUIRES having both microsoft word and Adobe Acrobat (I think the paid version).
There's ALL KINDS of cool astrophysics going on in here, like different kinds of variables (our interest is rotation, but we detect anything periodic). Stalling and rapid spin down, variability variations. Space cats. 🤯🔭🧪⭐ #exoplanets
Another RF classifier checks for signatures of aliasing/harmonics (also a common problem for TESS' 27-day sectors). 🤯🔭🧪⭐ #exoplanets You can see how powerful this is: the yellow dots are half or double the 'true' period, left is before the classifier and right is after. A HUGE improvement.
Bulk measurements of rotation periods is challenging, mostly because of systematics. You can see in this plot of stellar rotation vs TESS sector a clear wavy pattern. That's not astrophysical, it's from TESS (mostly scattered light from earth and moon and their observing pattern) 🤯🔭🧪⭐ #exoplanets
In context, it looks like most young planetary systems are aligned. Of course, this isn't significant yet. We need a lot more systems to be able to make statistical statements about alignments in young and old populations.
Still, it shows the characteristic wiggle of an aligned planet. It looks to be <20 degrees from perfect alignment, although the posterior has a very long tail due to an uncertain impact parameter 😭
Unfortunately, we missed ingress, which made the dataset a bit challenging to analyze.
The way this works is that the planet blocks preferentially redshifted or blueshifted light during transit, which manifests as a small RV anomaly. The shape of the anomaly tells you how well aligned the planet is. We observed TIDYE-1b with Maroon-X and LCO last November to measure this.
As a reminder, part of what made TIDYE-1b/IRAS04125+2902b interesting is that the planet has an inclination of ~90 (it transits), but it has a disk that's about 60-degrees off from that (almost face on)! There's a binary companion but it's also i~90.
🧪🔭⭐ Here’s a simple way to see it. In TIDYE, we’ve surveyed <10,000 young stars. Among them, we’ve found ~a dozen planets in the 4–12 Earth-radius range. Now take 10,000 Kepler stars and randomly draw planets of similar sizes. You should expect… ~3 planets. Not 12. That’s already a big difference.
🧪🔭⭐ “Isn’t that just observational bias? Aren’t young stars noisy, so you only find the large planets?” Partially true: we miss the small ones around young stars. Here’s the key point: The excess of large planets cannot be explained by bias. In fact, the bias works in the opposite direction.
🧪🔭⭐ #exoplanets #exoplanet Planet radius vs orbital period, color-coded by age. contours = the Kepler population. The new planet in this paper is marked with a ⭐. Even without statistics, your eyes will notice something: Young planets are big. Much bigger than the planets Kepler typically found.
🧪🔭⭐ #starclusters #pleiades Here’s what it would look like if every member were bright enough for the naked eye—seen from the Old Well on the UNC campus. Gorgeous artwork by grad student Isabel López Murillo. (A figure I’ll never get tired of.)
🧪🔭⭐ #starclusters #pleiades So what is this thing? A vast, ≥500 pc-wide association containing tens of thousands of stars—including many previously “independent” groups. We call it: The Greater Pleiades Complex.
🧪🔭⭐ #starclusters #pleiades The traceback is fascinating: these groups were closest to the Pleiades ≈80 Myr ago. But the Pleiades age is ≈120 Myr. We don’t think the age is wrong—we think the STRUCTURE broke apart ~80 Myr ago, likely after interacting with another molecular cloud.