Niamh O’Sullivan
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niamhk12.bsky.social
Niamh O’Sullivan
@niamhk12.bsky.social
900 followers 150 following 30 posts
DPhil student at the University of Oxford. A stellar physicist pretending to be an exoplanet finder 🌟🪐🌟
Posts Replies Media Videos
Reposted by Niamh O’Sullivan
Big congrats to Jennifer Burt, Xavier Dumusque, and Sam Halverson on finishing their epic (instant classic) Annual Reviews of Astronomy & Astrophysics article "Precise Radial Velocities"!
arxiv.org/abs/2511.01954
contains some great new graphics for talks on
#exoplanets #EPRV #DopplerSpectroscopy
November 5, 2025 at 7:20 AM
niamhk12.bsky.social
HARPS3 has definitely arrived at the INT (and I was only slightly excited to see it!) @terrahunting.bsky.social
Me pointing at HARPS3 below
October 29, 2025 at 6:21 PM
niamhk12.bsky.social
I’ve made it to La Palma where I’ll be spending the next week observing with the TNG! Here are some mandatory photos of the observatory 🔭🌟💫
The TNG as the sun sets Clouds rolling in over mountains The MAGIC telescope at night The William Hershel Telescope
October 27, 2025 at 4:07 PM
niamhk12.bsky.social
It’s happening!! Can’t believe I arrived in La Palma the same day!
terrahunting.bsky.social Terra Hunting Experiment @terrahunting.bsky.social · 27d
A dawn delivery to the Isaac Newton Telescope this morning ... HARPS3 shipping containers arrive!!!
October 24, 2025 at 2:30 PM
Reposted by Niamh O’Sullivan
oxoplanets.bsky.social
Great talk by @niamhk12.bsky.social on her talk at the Oxford Astrophysics Early Career Showcase! Teaching us all about supergranulation and the need to understand it in order to detect Earth twins!
October 6, 2025 at 1:59 PM
Reposted by Niamh O’Sullivan
caltechipac.bsky.social
The official number of exoplanets has surpassed 6,000! And you can access data on all 6,007 of them right here at IPAC 📈 🪐

Watch the video & read all about the center of the exoplanet universe (also known as NExScI!) here:
www.ipac.caltech.edu/news/the-nas...
September 18, 2025 at 12:19 AM
niamhk12.bsky.social
So excited for this!!!
terrahunting.bsky.social Terra Hunting Experiment @terrahunting.bsky.social · Sep 8
Today HARPS3 is leaving the nest and migrating south!
September 8, 2025 at 11:56 AM
Reposted by Niamh O’Sullivan
astroklein.bsky.social
Very excited to share that my new paper has been accepted for publication in MNRAS!
We are applying Doppler Imaging to model the activity signals from the HARPS-N Sun-as-a-star spectra! We show that injected planets can be retrieved with great accuracy!
ui.adsabs.harvard.edu/abs/2025MNRA... 🔭🪐🧪
August 28, 2025 at 2:01 PM
niamhk12.bsky.social
Sometimes the world is just beautiful
Sailing boat in front of a red moon
August 9, 2025 at 9:14 PM
Reposted by Niamh O’Sullivan
oxoplanets.bsky.social
Congrats to DPhil student Niamh on her incredible talk! Her work on supergranulation is helping to improve our ability to detect Earth like planets around sunlike stars! You can read more of her work here: arxiv.org/abs/2506.23693
July 4, 2025 at 11:19 AM
niamhk12.bsky.social
Had a great time at #eprv6 this week! We had a splinter session on supergranulation that led to some great discussions! Thank you to everyone who came!
July 4, 2025 at 11:04 AM
Reposted by Niamh O’Sullivan
astroarxiv.bsky.social
Measuring the Suns radial velocity variability due to supergranulation over a magnetic cycle. Niamh K. O'Sullivan et. al. https://arxiv.org/abs/2506.23693
Figure 1 Figure 2 Figure 3 Figure 4
July 1, 2025 at 7:58 AM
niamhk12.bsky.social
It’s paper day 🎉!! If you are interested in seeing how supergranulation changes over a solar cycle in RVs give it a read! arxiv.org/abs/2506.23693
Measuring the Suns radial velocity variability due to supergranulation over a magnetic cycle
In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity planet searches. We used eight years of Sun-as-a-star radial velocity ...
arxiv.org
July 1, 2025 at 8:07 AM
niamhk12.bsky.social
Excited to be at #eprv6 this week! If you are here and want to talk about supergranulation come find me!
EPRV6 title slide
June 30, 2025 at 10:25 AM
niamhk12.bsky.social
Had a great time learning all about PLATO and the PLATO-ESP conference in Marseille this week!
Niamh O’Sullivan presenting a slide on how much we need to observe stars to detect supergranulation.
June 27, 2025 at 3:39 PM
Reposted by Niamh O’Sullivan
vrubinobs.bsky.social
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
A sprawling, textured field of galaxies scattered across the deep black of space. It is filled with the delicate smudges and glowing cores of galaxies of many shapes, sizes and colors, as well as the bright multi-colored points of stars. The image focuses on a collection of interacting galaxies connected by delicate streams of stars. At top center lies a large elliptical galaxy that is dense and smooth, like a polished stone glowing with golden light. Like delicate spider silk or stretched taffy, these stellar bridges link the large elliptical to the few larger galaxies beneath, evidence of past collisions. All throughout the image, thousands of galaxies gather in clusters or are spread throughout, like glittering gems strewn on a table. Some are sharp-edged and spiral, like coiled ribbons; others round and diffuse, like polished pebbles. Still others are just smudges of various colors against the black of space. The background is peppered with pinpoint stars in reds, yellows, and blues, crisp against the velvet black. A cosmic tapestry of glowing tan and pink gas clouds with dark dust lanes. In the upper right, the Trifid Nebula resembles a small flower in space. Its soft, pinkish gas petals are surrounded by blue gas, and streaked with dark, finger-like veins of dust that divide it into three parts. It radiates a gentle, misty glow, diffuse and soft like the warmth of breath on a cold hand. To the lower left, the much larger Lagoon Nebula stretches wide like a churning sea of magenta gas, with bright blue, knotted clumps sprinkled throughout where new stars are born. Both nebulae are embedded in a soft tan backdrop of gas that is brighter on the left than on the right, etched with dark tendrils of dust and sprinkled with the pinpricks of millions of stars. A sprawling, textured field of galaxies scattered across the deep black of space. It is filled with the delicate smudges and glowing cores of galaxies of many shapes, sizes and colors, as well as the bright multi-colored points of stars. To the lower left is a region filled with the hundreds of golden glittering gems of a distant galaxy cluster. In the foreground, below and right of center, two blue spiral galaxies look like eyes beneath the entangled mass of a triple galaxy merger in the upper right. A few bright blue points of foreground stars pierce the glittering tapestry. All throughout the image, thousands of galaxies gather in clusters or are spread throughout, like glittering gems strewn on a table. Some are sharp-edged and spiral, like coiled ribbons; others round and diffuse, like polished pebbles. Still others are just smudges of various colors against the black of space. The background is peppered with pinpoint stars in reds, yellows, and blues, crisp against the velvet black.
June 23, 2025 at 4:06 AM
Reposted by Niamh O’Sullivan
maosbot.bsky.social
Don't sleep on Gaussian processes. Most under-rated model class on this or any other planet (we've used Gaussian processes to study exo-planets!)
June 21, 2025 at 9:19 AM
Reposted by Niamh O’Sullivan
astrojake.bsky.social
Spent the evening at @wolfsonoxford.bsky.social learning about astronomy in ancient Mesopotamia! It was fascinating!
May 28, 2025 at 7:12 PM
niamhk12.bsky.social
We had a great talk by @moudhy.bsky.social at @wolfsonoxford.bsky.social AstroClub this evening! Thank you so much to everyone who came along and especially to Moudhy for such a great talk!
Halley’s Comet and recordings of the comet from 164 BCE Calculations of distance travelled by Jupiter from ancient clay tablets
May 28, 2025 at 8:44 PM
Reposted by Niamh O’Sullivan
terrahunting.bsky.social
... and the picture of the grism in its holder just before installation - how beautiful is this?!
May 28, 2025 at 1:11 PM
niamhk12.bsky.social
Come join us if you are interested in astronomy, history, or both! Should be a great event!
wolfsonoxford.bsky.social Wolfson College Oxford @wolfsonoxford.bsky.social · May 28
Tonight in the LWA, @moudhy.bsky.social will discuss the nightly astrological observations of scholars from ancient Assyria and Babylonia, sometimes interpreted as divine messages about forthcoming events. Hosted by Wolfson AstroClub, not to be missed! 🔭 🌠

www.wolfson.ox.ac.uk/event/readin...
Reading the "Heavenly Writing": Observational astronomy in ancient Assyria and Babylonia - Wolfson College
A Wolfson AstroClub talk offering a survey of the works left behind by early astronomers, followed by telescope observing.
www.wolfson.ox.ac.uk
May 28, 2025 at 10:27 AM
niamhk12.bsky.social
Happy May Morning from Oxford 🌸 🌺🌻
May 1, 2025 at 12:46 PM
niamhk12.bsky.social
Quite the venue for #Discuss2025!
Oxford town hall, with slide on the criteria for a good solvent life
April 23, 2025 at 9:02 AM
Reposted by Niamh O’Sullivan
emily.space
Reading more about this, I'm disappointed in the authors of this study & how they've turned a very marginal result into worldwide press releases.

In this climate, we as scientists have a responsibility to lead by example and represent our work accurately to the press. This is not that. ☄️🔭🧪
chrislintott.bsky.social Chris Lintott @chrislintott.bsky.social · Apr 17
An astonishing headline reporting on new observations from a team led to Nikku Madhusudhan claims they’ve found ‘hints of life’ on a planet orbiting a dwarf star some 124 light years away. What’s going on? (1/n) www.bbc.co.uk/news/article... 🔭 🧪
Promising hints of life found on distant planet K2-18b
Scientists find new but tentative evidence that a faraway world orbiting another star may be home to life.
www.bbc.co.uk
April 17, 2025 at 8:02 AM
Reposted by Niamh O’Sullivan
terrahunting.bsky.social
Hello World!
April 6, 2025 at 5:36 PM