Dr./Prof. Meredith MacGregor
@mmacgreg.bsky.social
Assistant Professor at Johns Hopkins in the Department of Physics and Astronomy | astronomer, educator, runner, mom | Pronouns: she/her
Our AAS Education Committee report on 'The Landscape of Undergraduate Astronomy and Astrophysics Degree Requirements' is now available on arXiv: www.arxiv.org/abs/2602.03959. Please give it a read!
The Landscape of Undergraduate Astronomy and Astrophysics Degree Requirements
In this document we summarize the results of a survey of undergraduate degree-granting programs conducted by the 2024-2025 American Astronomical Society Education Committee's Subcommittee on UndeRgrad...
www.arxiv.org
February 5, 2026 at 5:22 PM
Our AAS Education Committee report on 'The Landscape of Undergraduate Astronomy and Astrophysics Degree Requirements' is now available on arXiv: www.arxiv.org/abs/2602.03959. Please give it a read!
Some new recommendations from our AAS Working Group on Graduate Admission: aas.org/posts/news/2...
AAS Working Group Recommends New Best Practices for Graduate Admissions
The Working Group on Graduate Admissions wishes to highlight two recommendations for immediate adoption by the community to improve the current astronomy-wide graduate admissions process.
aas.org
January 29, 2026 at 3:13 AM
Some new recommendations from our AAS Working Group on Graduate Admission: aas.org/posts/news/2...
So excited to see our EVE science highlighted in Evgenya Shkolnik’s fantastic plenary at #AAS247! I’m thrilled to be proposing this mission to NASA
January 8, 2026 at 11:26 PM
So excited to see our EVE science highlighted in Evgenya Shkolnik’s fantastic plenary at #AAS247! I’m thrilled to be proposing this mission to NASA
IRSTIG splinter now in Room 231!
January 7, 2026 at 10:36 PM
IRSTIG splinter now in Room 231!
And now it’s the PRIMA special session in Room 224B!
January 7, 2026 at 9:00 PM
And now it’s the PRIMA special session in Room 224B!
First up are a bunch of talks (including mine!) about the POEMM balloon mission in the 10am session in Room 222C
January 7, 2026 at 5:07 PM
First up are a bunch of talks (including mine!) about the POEMM balloon mission in the 10am session in Room 222C
It’s far-infrared day at #AAS247! Come learn about how cool this part of the spectrum is and why it is critical for a multi-wavelength understanding of the universe!
January 7, 2026 at 5:07 PM
It’s far-infrared day at #AAS247! Come learn about how cool this part of the spectrum is and why it is critical for a multi-wavelength understanding of the universe!
Come join us in the session discussing our report on the landscape of undergraduate degrees in astronomy and astrophysics at #AAS247 in room 226B!
January 5, 2026 at 9:03 PM
Come join us in the session discussing our report on the landscape of undergraduate degrees in astronomy and astrophysics at #AAS247 in room 226B!
What a great birthday present today - SMEX is back on! Let’s go EVE!
January 5, 2026 at 6:47 PM
What a great birthday present today - SMEX is back on! Let’s go EVE!
Pretty excited to be part of this awesome team doing super cool science! arxiv.org/abs/2512.07695
JWST TRAPPIST-1 e/b Program: Motivation and first observations
One of the forefront goals in the field of exoplanets is the detection of an atmosphere on a temperate terrestrial exoplanet, and among the best suited systems to do so is TRAPPIST-1. However, JWST tr...
arxiv.org
December 10, 2025 at 2:39 PM
Pretty excited to be part of this awesome team doing super cool science! arxiv.org/abs/2512.07695
Oiselle! They make running clothes specifically for women and are amazing in all seasons!
December 4, 2025 at 7:25 PM
Oiselle! They make running clothes specifically for women and are amazing in all seasons!
Reposted by Dr./Prof. Meredith MacGregor
1/ It's press day!🔭🧪 We apply a grid of time-dependent physical models to explain TRAPPIST-1 flares, predicting the X-ray & UV flux driving escape and photochemistry in planetary atmospheres, and correcting flare contamination in transit spectroscopy down to ~60 ppm:
www.colorado.edu/today/2025/1...
www.colorado.edu/today/2025/1...
New research on flares from a hot-tempered star could inform search for habitable planets
A new study takes a close look at TRAPPIST-1, a little star roughly 40 light-years from our sun that hosts seven Earth-sized planets.
www.colorado.edu
December 4, 2025 at 6:53 PM
1/ It's press day!🔭🧪 We apply a grid of time-dependent physical models to explain TRAPPIST-1 flares, predicting the X-ray & UV flux driving escape and photochemistry in planetary atmospheres, and correcting flare contamination in transit spectroscopy down to ~60 ppm:
www.colorado.edu/today/2025/1...
www.colorado.edu/today/2025/1...
I always go more formal just to be sure that they treat the applicant like every other applicant. But, really either should be fine!
December 3, 2025 at 9:40 PM
I always go more formal just to be sure that they treat the applicant like every other applicant. But, really either should be fine!
Today is the ExoJamboree at @jhuartssciences.bsky.social and @stsci.edu - How cool is that we are such a powerhouse of exoplanet research here that we can have an awesome conference with just local people?!?!
November 21, 2025 at 7:04 PM
Today is the ExoJamboree at @jhuartssciences.bsky.social and @stsci.edu - How cool is that we are such a powerhouse of exoplanet research here that we can have an awesome conference with just local people?!?!
Another wonderful article about our RZ Psc work!
I was tempted to make this post "Avi Loeb Claims Millions of Spaceships Found" but decided against it.
www.scientificamerican.com/article/alie...
🔭 🧪
www.scientificamerican.com/article/alie...
🔭 🧪
Alien Comets Swarm around Other Stars
Comets don’t just orbit our sun. “Exocomets” are common around other stars in the galaxy, too
www.scientificamerican.com
November 21, 2025 at 2:41 PM
Another wonderful article about our RZ Psc work!
Believe me I had that same thought writing that paper 😂
November 21, 2025 at 2:41 PM
Believe me I had that same thought writing that paper 😂
This! Here's a slide pulled from my class lecture notes this semester. Comets have two clear tails - one from dust and one from ions. They point in different directions because one feels the solar wind while the other feels radiation pressure.
November 14, 2025 at 4:03 PM
This! Here's a slide pulled from my class lecture notes this semester. Comets have two clear tails - one from dust and one from ions. They point in different directions because one feels the solar wind while the other feels radiation pressure.
Nature published a research highlight on our RZ PSc exocomet paper: www.nature.com/articles/d41...
A host of ‘exocomets’ swarms a distant star
Dimming of the starlight from RZ Piscium reveals that 24 unseen bodies are whizzing around the star.
www.nature.com
November 11, 2025 at 7:57 PM
Nature published a research highlight on our RZ PSc exocomet paper: www.nature.com/articles/d41...
Flying to Rochester today to give the colloquium. Can confirm that most of security at BWI is shut down and people aren’t happy about it 🫠
November 2, 2025 at 7:38 PM
Flying to Rochester today to give the colloquium. Can confirm that most of security at BWI is shut down and people aren’t happy about it 🫠
So excited that our paper is finally out! We analyzed archival TESS observations of RZ Psc and detected 24 transiting exocomets. And, Adalyn is an amazing undergrad applying for grad school this year!
Gibson et al. “TESS Discovers a Second System of Transiting Exocomets in the Extreme
Debris Disk of RZ Psc” showing 24 exocomet transits and the existence of a broken power law for the sizes of these exocomets, unlike Beta Pic’s exocomet distribution #exoplanet #astrodon #astrosci
Debris Disk of RZ Psc” showing 24 exocomet transits and the existence of a broken power law for the sizes of these exocomets, unlike Beta Pic’s exocomet distribution #exoplanet #astrodon #astrosci
October 14, 2025 at 1:19 PM
So excited that our paper is finally out! We analyzed archival TESS observations of RZ Psc and detected 24 transiting exocomets. And, Adalyn is an amazing undergrad applying for grad school this year!
Never hurts to reach out! It helps you figure out whether you actually want to work with that person. And, it can help you make a better justification for the host institution.
October 14, 2025 at 1:17 PM
Never hurts to reach out! It helps you figure out whether you actually want to work with that person. And, it can help you make a better justification for the host institution.
Ugh that all sounds terrible! (The fact that I started my new biologic injections the same week is definitely not helping... So far, Mom is the hardest hit. Dad is fine. Dogs are fine. Little one had the sniffles and bounced back within a few days.)
September 17, 2025 at 4:20 PM
Ugh that all sounds terrible! (The fact that I started my new biologic injections the same week is definitely not helping... So far, Mom is the hardest hit. Dad is fine. Dogs are fine. Little one had the sniffles and bounced back within a few days.)
Our little one started daycare last week, and I have been sick ever since... My immune system is clearly no match to school germs!
September 17, 2025 at 4:08 PM
Our little one started daycare last week, and I have been sick ever since... My immune system is clearly no match to school germs!
Calling the Astronomy hive mind! Who is your favorite deceased astronomer that deserves to have something named after them posthumously? And why?
September 11, 2025 at 10:24 PM
Calling the Astronomy hive mind! Who is your favorite deceased astronomer that deserves to have something named after them posthumously? And why?