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
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!
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?
Reposted by Dr./Prof. Meredith MacGregor
National Radio Astronomy Observatory: Neighboring Star’s Warped Ring Shaped by Evolving Planets public.nrao.edu/news/neighbo...
Neighboring Star’s Warped Ring Shaped by Evolving Planets - National Radio Astronomy Observatory
Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made the highest resolution image to date, revealing new insights...
public.nrao.edu
September 8, 2025 at 2:28 PM
National Radio Astronomy Observatory: Neighboring Star’s Warped Ring Shaped by Evolving Planets public.nrao.edu/news/neighbo...
Super excited that these results are finally out! This is the highest resolution ALMA image of Fomalhaut ever, and we can learn new things about the structure of the disk and the planet that is likely shaping it. Press release here: public.nrao.edu/news/neighbo...
Neighboring Star’s Warped Ring Shaped by Evolving Planets - National Radio Astronomy Observatory
Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made the highest resolution image to date, revealing new insights...
public.nrao.edu
September 4, 2025 at 5:21 PM
Super excited that these results are finally out! This is the highest resolution ALMA image of Fomalhaut ever, and we can learn new things about the structure of the disk and the planet that is likely shaping it. Press release here: public.nrao.edu/news/neighbo...
It's the first day of classes and I spent the weekend in the hospital with a sick little one who needed emergency surgery... Let's do this! (Also, please send coffee!)
a sign that says " what is even happening " next to a dumpster
ALT: a sign that says " what is even happening " next to a dumpster
media.tenor.com
August 25, 2025 at 3:57 PM
It's the first day of classes and I spent the weekend in the hospital with a sick little one who needed emergency surgery... Let's do this! (Also, please send coffee!)
Perfect evening for the department welcome crab feast @jhuartssciences.bsky.social! 🦀
August 22, 2025 at 9:37 PM
Perfect evening for the department welcome crab feast @jhuartssciences.bsky.social! 🦀
Challenge: post your last photo taken in DC to show what a hell-hole it is.
August 12, 2025 at 2:32 AM
Challenge: post your last photo taken in DC to show what a hell-hole it is.
Back for another day of #HWO25 at the stunning at the @jhuartssciences.bsky.social Bloomberg Center!
July 29, 2025 at 12:30 PM
Back for another day of #HWO25 at the stunning at the @jhuartssciences.bsky.social Bloomberg Center!
Wow wow wow 🤩 It’s just amazing what we humans can do when we support scientific research and funding
Introducing...your sneak peek at the cosmos captured by NSF–DOE Vera C. Rubin Observatory!
Can you guess these regions of sky?
This is just a small peek...join us at 11am US EDT for your full First Look at how Rubin will #CaptureTheCosmos! 🔭🧪
#RubinFirstLook
ls.st/rubin-first-look-livestream
Can you guess these regions of sky?
This is just a small peek...join us at 11am US EDT for your full First Look at how Rubin will #CaptureTheCosmos! 🔭🧪
#RubinFirstLook
ls.st/rubin-first-look-livestream
June 23, 2025 at 12:38 PM
Wow wow wow 🤩 It’s just amazing what we humans can do when we support scientific research and funding
Great article, @hannah-richter.bsky.social!
The White House's proposed budget for NASA is "a whole new level of horror," according to one planetary scientist. 🚀❌ Read how the space science community is reeling and dealing in my new story for @skyandtelescope.bsky.social #nasa #trump skyandtelescope.org/astronomy-ne...
Proposed NASA Budget Would Gut Space Science, Jobs
With more than 40 missions on the chopping block, the space community is holding on to hope that the budget is “dead on arrival” in Congress
skyandtelescope.org
June 3, 2025 at 7:12 PM
Great article, @hannah-richter.bsky.social!
The report from our AAS Task Force on Graduate Admission is out! This has become a complicated problem in recent years, and is made even worse with the recent federal budget. You can read the report here: arxiv.org/abs/2505.09759
AAS Graduate Admissions Task Force: Final report and recommendations
In March of 2024 the AAS formed our Graduate Admissions Task Force (GATF), asking us to produce recommendations aimed at improving the state of graduate admissions in astronomy. The task was a timely ...
arxiv.org
June 2, 2025 at 2:54 PM
The report from our AAS Task Force on Graduate Admission is out! This has become a complicated problem in recent years, and is made even worse with the recent federal budget. You can read the report here: arxiv.org/abs/2505.09759
The NSF hasn't fared any better including completely eliminating postdoctoral fellowships. I was an NSF AAPF. That program is responsible for me getting to where I am now. We will lose so many early career scientists because of this.
nsf-gov-resources.nsf.gov/files/00-NSF...
nsf-gov-resources.nsf.gov/files/00-NSF...
nsf-gov-resources.nsf.gov
May 30, 2025 at 9:02 PM
The NSF hasn't fared any better including completely eliminating postdoctoral fellowships. I was an NSF AAPF. That program is responsible for me getting to where I am now. We will lose so many early career scientists because of this.
nsf-gov-resources.nsf.gov/files/00-NSF...
nsf-gov-resources.nsf.gov/files/00-NSF...
Reposted by Dr./Prof. Meredith MacGregor
The president's budget request for NSF FY26 is also out. It zeroes out the NSF astronomy & astrophysics and NSF MPS ASCEND postdoc fellowships. nsf-gov-resources.nsf.gov/files/00-NSF...
nsf-gov-resources.nsf.gov
May 30, 2025 at 8:52 PM
The president's budget request for NSF FY26 is also out. It zeroes out the NSF astronomy & astrophysics and NSF MPS ASCEND postdoc fellowships. nsf-gov-resources.nsf.gov/files/00-NSF...
The President's Budget Request for NASA is out - What a disaster for astrophysics! Numerous missions already in development are canceled. It is well past time for all of us to raise our voices if we value science in this country.
You can find the documents here:
www.nasa.gov/fy-2026-budg...
You can find the documents here:
www.nasa.gov/fy-2026-budg...
FY 2026 Budget Request - NASA
Fiscal Year 2026 Budget Request
www.nasa.gov
May 30, 2025 at 8:57 PM
The President's Budget Request for NASA is out - What a disaster for astrophysics! Numerous missions already in development are canceled. It is well past time for all of us to raise our voices if we value science in this country.
You can find the documents here:
www.nasa.gov/fy-2026-budg...
You can find the documents here:
www.nasa.gov/fy-2026-budg...
Missed this yesterday because I was on an airplane but check out this video highlighting grad student Kiana Burton’s awesome thesis work!
AAS JOURNALS AUTHOR SERIES
Meredith MacGregor @mmacgreg.bsky.social (Johns Hopkins University) chats with Frank Timmes about her article on Proxima Centauri: youtu.be/sf_hA1u0fUE
This series connects authors with their article, their human story & the larger #astronomy community. #TheGoodStuff 🔭
Meredith MacGregor @mmacgreg.bsky.social (Johns Hopkins University) chats with Frank Timmes about her article on Proxima Centauri: youtu.be/sf_hA1u0fUE
This series connects authors with their article, their human story & the larger #astronomy community. #TheGoodStuff 🔭
AAS Journal Author Series: Meredith MacGregor on 2025ApJ...982...43B
YouTube video by AAS
youtu.be
May 25, 2025 at 1:41 AM
Missed this yesterday because I was on an airplane but check out this video highlighting grad student Kiana Burton’s awesome thesis work!
Great write-up about an interdisciplinary project I've been working on to apply topological data analysis (TDA) to ALMA data: www.siam.org/publications...
Computational Topology to Find Exoplanet Signatures in Astronomical Images | SIAM
Elizabeth Bradley presented mathematical approaches to enhance the characterization of structures that signify exoplanet formation at DS25.
www.siam.org
May 22, 2025 at 6:53 PM
Great write-up about an interdisciplinary project I've been working on to apply topological data analysis (TDA) to ALMA data: www.siam.org/publications...
Excited to be at this workshop this week and talk about all of the exciting science we can do in the far-infrared!
Working meeting on 'PRIMA and the Future of Far-IR Science' happening today on the Caltech campus hosted by @caltechipac.bsky.social! Agenda here: conference.ipac.caltech.edu/prima-pasade...
prima-pasadena2025
conference.ipac.caltech.edu
May 19, 2025 at 5:14 PM
Excited to be at this workshop this week and talk about all of the exciting science we can do in the far-infrared!
It’s Physics Fair day at Johns Hopkins! @jhuartssciences.bsky.social
April 26, 2025 at 8:08 PM
It’s Physics Fair day at Johns Hopkins! @jhuartssciences.bsky.social
Reposted by Dr./Prof. Meredith MacGregor
The American Astronomical Society is gravely concerned by the deep cuts to NASA science funding reported to be in the draft President’s Budget Request for Fiscal Year 2026. Read more here: aas.org/press/aas-st... and take action now: aas.org/urge-nasa-su...
April 11, 2025 at 8:04 PM
The American Astronomical Society is gravely concerned by the deep cuts to NASA science funding reported to be in the draft President’s Budget Request for Fiscal Year 2026. Read more here: aas.org/press/aas-st... and take action now: aas.org/urge-nasa-su...
This would be catastrophic for US science. Period.
arstechnica.com/space/2025/0...
arstechnica.com/space/2025/0...
Trump White House budget proposal eviscerates science funding at NASA
“This would decimate American leadership in space.”…
arstechnica.com
April 11, 2025 at 7:26 PM
This would be catastrophic for US science. Period.
arstechnica.com/space/2025/0...
arstechnica.com/space/2025/0...
Reposted by Dr./Prof. Meredith MacGregor
"What does NASA do for us?"
You might think NASA only benefits Americans in Florida or Texas. You'd be wrong. 🔭🧪
www.nasa.gov/fy-2023-econ...
You might think NASA only benefits Americans in Florida or Texas. You'd be wrong. 🔭🧪
www.nasa.gov/fy-2023-econ...
April 11, 2025 at 5:20 PM
"What does NASA do for us?"
You might think NASA only benefits Americans in Florida or Texas. You'd be wrong. 🔭🧪
www.nasa.gov/fy-2023-econ...
You might think NASA only benefits Americans in Florida or Texas. You'd be wrong. 🔭🧪
www.nasa.gov/fy-2023-econ...