Sierra Grant
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sierragrant.bsky.social
Sierra Grant
@sierragrant.bsky.social
160 followers 120 following 29 posts
Carnegie Fellow at the Earth and Planets Laboratory. Protoplanetary + circumplanetary disks. Formerly at MPE, BU, and University of Michigan. She/her. #BiInSci 🏳️‍🌈✨🔭 Opinions are my own.
sierragrant.com
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Reposted by Sierra Grant
astronemly.bsky.social
Why? NASA is a crown jewel of US science and an international inspiration. Its logo adorns hoodies worn by young and old. The most famous telescopes could not have existed without Goddard and shutting down parts of it, even temporarily, cuts off the life blood for future missions. Why kill NASA?!?
November 4, 2025 at 9:18 PM
Reposted by Sierra Grant
aasnova.org
AAS Nova turned 10 this year! For our 2,000th post, we’re looking back on the past decade of astronomy research. aasnova.org/2025/10/03/a... @aas.org 🔭🧪
AAS Nova Celebrates 10 Years of Astronomy Research News
AAS Nova turned 10 this year! For our 2,000th post, we're looking back on the past decade of astronomy research.
aasnova.org
October 3, 2025 at 4:11 PM
Reposted by Sierra Grant
science.esa.int
Moon formation drama, a bit more understood 🌚

The NASA/ESA/CSA James Webb Space Telescope has found evidence of a ‘construction yard’ for moons around a large exoplanet, CT Cha b, which lies 625 light-years from Earth.

Read more 👉 www.esa.int/Science_Expl... 🔭 🧪 ☄️
This is an illustration of a young planet with a surrounding disc of dust and gas, potentially forming moons. The planet, which appears red, is shown at lower right, enveloped by a cloudy disc. The host star appears at upper left, and glows yellow, with its own reddish disc of debris. The black background of space is speckled with stars. At the bottom of the illustration, graphics of molecules are listed in the following order: Acetylene, Carbon Dioxide, Ethane, Benzene, Hydrogen cyanide.
September 29, 2025 at 2:11 PM
Reposted by Sierra Grant
mattkenworthy.bsky.social
Cugno and Grant @sierragrant.bsky.social with “A Carbon-rich Disk Surrounding a Planetary-mass Companion” detected using #JWST - an impressive detection of several different carbon molecules that are very promising for #exomoon formation around the directly imaged #exoplanet CT Cha b ☄
An image of the planetary companion CT Cha b shown as a red dot next to its parent star, with a spectrum from 12 to 16 microns from JWST showing several rotational and vibrational bands in emission for several carbon molecules.
September 30, 2025 at 7:34 AM
Reposted by Sierra Grant
press.aas.org
Space Telescope Science Institute: NASA’s JWST Studies Moon-Forming Disk Around Massive Planet science.nasa.gov/science-rese...
NASA’s Webb Telescope Studies Moon-Forming Disk Around Massive Planet - NASA Science
NASA’s James Webb Space Telescope has provided the first direct measurements of the chemical and physical properties of a potential moon-forming disk
science.nasa.gov
September 29, 2025 at 5:04 PM
Reposted by Sierra Grant
tamburo.bsky.social
SO PROUD OF MY (FUTURE*) WIFE @sierragrant.bsky.social

*FUTURE MEANING SUNDAY
stsci.edu Space Telescope Science Institute @stsci.edu · Sep 29
#NASAWebb has found the first direct evidence of potential moon formation around a giant exoplanet. The discovery is shedding light on how such systems evolve and why moons could be potentially habitable worlds: https://bit.ly/46xGodN 🔭 🧪
An illustration of a young planet with a surrounding disk of dust and gas potentially forming moons. The planet, which appears dark red, is shown at lower right, circled by a cloudy, clumpy reddish orange-colored disk. The host star appears at upper left, and glows yellow, with its own reddish disk of debris. The disk that surrounds the planet takes up about half the illustration. The black background of space is speckled with stars. At the bottom of the illustration, graphics of molecules are listed in the following order: Acetylene, Carbon Dioxide, Ethane, Benzene, Hydrogen cyanide. The words Artist’s Concept appear at upper right.
September 29, 2025 at 2:10 PM
sierragrant.bsky.social
PRESS RELEASE DAY! Could not be prouder of this result and so happy that it's now out!!! 🤩✨

Thanks to the team at @stsci.edu for the wonderful write-up and image!
stsci.edu Space Telescope Science Institute @stsci.edu · Sep 29
#NASAWebb has found the first direct evidence of potential moon formation around a giant exoplanet. The discovery is shedding light on how such systems evolve and why moons could be potentially habitable worlds: https://bit.ly/46xGodN 🔭 🧪
An illustration of a young planet with a surrounding disk of dust and gas potentially forming moons. The planet, which appears dark red, is shown at lower right, circled by a cloudy, clumpy reddish orange-colored disk. The host star appears at upper left, and glows yellow, with its own reddish disk of debris. The disk that surrounds the planet takes up about half the illustration. The black background of space is speckled with stars. At the bottom of the illustration, graphics of molecules are listed in the following order: Acetylene, Carbon Dioxide, Ethane, Benzene, Hydrogen cyanide. The words Artist’s Concept appear at upper right.
September 29, 2025 at 4:09 PM
Reposted by Sierra Grant
carnegiescience.bsky.social
TOMORROW: Two talks, one big night of discovery!

Join Earth & Planets Laboratory postdocs Sierra Grant & Shubham Kanodia as they reveal how planets are born—and the giants that defy the rules. #NeighborhoodLecture

📅 Sept 25 | 6:30 PM ET | DC & Online
🔗 RSVP: carnegiescience.edu/birth-worlds...
Birth of Worlds, Rise of Giants
Join Carnegie postdocs Shubham Kanodia and Sierra Grant as they explore the secrets of distant worlds—from the birth of new planets to giant rule-breakers that defy expectations—in a special double…
carnegiescience.edu
September 24, 2025 at 5:37 PM
Reposted by Sierra Grant
miquai.bsky.social
The best part of my job is the people I get to work with 🪐💙
Three planeteers look through a mockup of a Curiosity rover wheel
September 21, 2025 at 1:57 AM
Reposted by Sierra Grant
nplinnspace.bsky.social
🤯🤯🤯 circumstellar disk chemistry? No, circumPLANETARY disk chemistry!

What an INCREDIBLE result! Check it out below ⬇️🧪🔭🪐
sierragrant.bsky.social Sierra Grant @sierragrant.bsky.social · Sep 19
Today is a special paper day for me: for the first time we can do chemistry in a circumplanetary disk around a planetary-mass companion! Gabriele Cugno and I used JWST to tease out the signal of CT Cha b, finding a rich carbon chemistry (7 molecules + 1 isotopolog detected)! arxiv.org/abs/2509.15209
September 19, 2025 at 4:13 PM
Reposted by Sierra Grant
tamburo.bsky.social
🪐🔭 JWST is letting us learn about disks around PLANETARY-MASS OBJECTS!!!
sierragrant.bsky.social Sierra Grant @sierragrant.bsky.social · Sep 19
Today is a special paper day for me: for the first time we can do chemistry in a circumplanetary disk around a planetary-mass companion! Gabriele Cugno and I used JWST to tease out the signal of CT Cha b, finding a rich carbon chemistry (7 molecules + 1 isotopolog detected)! arxiv.org/abs/2509.15209
September 19, 2025 at 3:57 PM
sierragrant.bsky.social
Today is a special paper day for me: for the first time we can do chemistry in a circumplanetary disk around a planetary-mass companion! Gabriele Cugno and I used JWST to tease out the signal of CT Cha b, finding a rich carbon chemistry (7 molecules + 1 isotopolog detected)! arxiv.org/abs/2509.15209
September 19, 2025 at 3:22 PM
sierragrant.bsky.social
Feel free to reach out if you have any questions about Carnegie! It's an amazing place to be a postdoc!
johannateske.bsky.social Johanna Teske @johannateske.bsky.social · Sep 4
The advertisement for Carnegie EPL's 2026 postdoctoral fellowship is out! aas.org/jobregister/... We are also happy to host external fellowships like NHFP, NSF, and 51 Peg b (the latter is due Oct 3rd, one month away!). Please feel free to reach out if you have questions. (1/2)
aas.org
September 4, 2025 at 1:18 AM
sierragrant.bsky.social
Another MINDS JWST paper! We explore the stark transition from H2O-dominated spectra in Sun-like systems to the carbon-rich chemistry seen for low-mass objects. We don't know exactly what is driving this trend, but we explore the possibilities that may be acting in concert.
arxiv.org/pdf/2508.04692
August 7, 2025 at 3:33 PM
sierragrant.bsky.social
New MINDS paper from Nicolas Kurtovic, focused on binary systems. Spectra, extended emission, variability, multi-observatory analysis -- there's something for everyone!
arxiv.org/pdf/2508.02576
August 5, 2025 at 6:49 PM
sierragrant.bsky.social
Our cat, but now in spherical form 😍
tamburo.bsky.social Patrick Tamburo @tamburo.bsky.social · Jun 17
And here's the 40-degree spherical harmonic expansion of my cat 😭😭😭
June 17, 2025 at 6:42 PM
sierragrant.bsky.social
A spotted star, a (very!) misaligned planet, and awesome gifs, what more could you want?! 🤩
tamburo.bsky.social Patrick Tamburo @tamburo.bsky.social · Jun 16
TOI-3884 b is a planet around an M dwarf whose transits show persistent spot crossings. We show that the star's rotational and spot-crossing variations can be modeled with a misaligned planet transiting a large polar spot (confirming last week's results from Mori et al.)
arxiv.org/abs/2506.11998
June 16, 2025 at 2:40 PM
Reposted by Sierra Grant
tamburo.bsky.social
Now published in AJ! We used Tierras to measure the 23-day rotation period of a K dwarf and found that the orbit of its transiting planet is aligned with the star's spin axis. Stay tuned as we measure true obliquities for a larger sample!

iopscience.iop.org/article/10.3...
June 13, 2025 at 5:55 PM
sierragrant.bsky.social
Great work by Kielan Hoch and team on this incredible two-planet system!! We will revisit this target with MIRI-MRS next year to hunt for molecules in the disk around planet b, in a program led by Gabriele Cugno and me, and with Kielan's expertise on the system 🥳🪐
June 11, 2025 at 12:10 AM
Reposted by Sierra Grant
mikeokuda.bsky.social
Save NASA Science: Please join me in signing this petition from The Planetary Society, urging Congress to reject the deep cuts to science that have been proposed by the administration. www.planetary.org/advocacy-act...
Advocacy Action Center
The Planetary Society is organizing a new space constituency that is educated, empowered, and loud.
www.planetary.org
June 1, 2025 at 9:47 PM
sierragrant.bsky.social
〰️〰️〰️〰️ New paper from @tamburo.bsky.social! 🤩
May 7, 2025 at 4:11 PM
Reposted by Sierra Grant
megadeath.bsky.social
The data produced by this group has been an essential resource for so much great science. We use their data and websites to interpret our JWST spectra of protostars. It is exactly the kind of foundational investments the US should be making to advance science. www.change.org/p/oppose-the...
Sign the Petition
Oppose the layoff of the NIST Atomic Spectroscopy Group
www.change.org
April 17, 2025 at 4:35 PM
Reposted by Sierra Grant
miquai.bsky.social
I received a heartbreaking email today: A paper in a special issue I’m editing is being retracted because one of its authors is afraid of losing their job and their legal status in the U.S. if they publish a scientific study on evolution. Yes, on evolution, nature's engine of diversity.
March 29, 2025 at 11:52 PM
Reposted by Sierra Grant
johannateske.bsky.social
Framed copy of 2002 Gruber Cosmology Prize awarded to Vera Rubin, which reads, “Her pioneering studies of the deviations of galaxy motions from classical a Hubble theory demonstrated that large scale structure existed in the universe. Her discovery that most of the universe is unseen dark matter derived from her exploration of the rotation of spiral galaxies. By example and gentle voice she has championed equal rights and revealed the incredible beauty of the universe.”
January 31, 2025 at 12:21 AM
Reposted by Sierra Grant
maxplanck.de
Here is a highly recommended thread that summarizes what has happened in scientific landscape in the US since Trump's inauguration. It makes for dystopian reading ⬇️
carlzimmer.com Carl Zimmer @carlzimmer.com · Jan 28
American science and medicine has been thrown into chaos and uncertainty over the past week. Here are some stories to get up to speed. 1/12
January 28, 2025 at 9:18 AM