Denis Erkal
@derkal.bsky.social
Astrophysicist working on dark matter, near-field cosmology, and galaxy formation. All opinions are my own. He/him.
Reposted by Denis Erkal
Honored to receive the 2026 American Physical Society Edward A. Bouchet Award!
To see how the DEI ban in Ohio influences our university, please see the OSU announcement of the award (left) vs the actual APS citation for the award (right).
To see how the DEI ban in Ohio influences our university, please see the OSU announcement of the award (left) vs the actual APS citation for the award (right).
November 13, 2025 at 8:59 PM
Honored to receive the 2026 American Physical Society Edward A. Bouchet Award!
To see how the DEI ban in Ohio influences our university, please see the OSU announcement of the award (left) vs the actual APS citation for the award (right).
To see how the DEI ban in Ohio influences our university, please see the OSU announcement of the award (left) vs the actual APS citation for the award (right).
Reposted by Denis Erkal
We come with receipts🧾
Tidal tails are cosmic “receipts” of galactic drama, showing who collided with whom. Rubin's camera is sharp enough to catch wind of even the faintest intergalactic tea.
No need to worry about "pics or it didn't happen" with Rubin keeping a close eye 😎 🔭🧪
Tidal tails are cosmic “receipts” of galactic drama, showing who collided with whom. Rubin's camera is sharp enough to catch wind of even the faintest intergalactic tea.
No need to worry about "pics or it didn't happen" with Rubin keeping a close eye 😎 🔭🧪
October 24, 2025 at 10:05 PM
We come with receipts🧾
Tidal tails are cosmic “receipts” of galactic drama, showing who collided with whom. Rubin's camera is sharp enough to catch wind of even the faintest intergalactic tea.
No need to worry about "pics or it didn't happen" with Rubin keeping a close eye 😎 🔭🧪
Tidal tails are cosmic “receipts” of galactic drama, showing who collided with whom. Rubin's camera is sharp enough to catch wind of even the faintest intergalactic tea.
No need to worry about "pics or it didn't happen" with Rubin keeping a close eye 😎 🔭🧪
Reposted by Denis Erkal
Paper day! My PhD student Mariana Júlio, with @readdark.bsky.social, @pengfeili.bsky.social and others, studies the internal dynamics of dwarf galaxies and finds they don't agree with the Radial Acceleration Relation, challenging the dark matter alternative MOND.
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
The radial acceleration relation at the EDGE of galaxy formation: testing its universality in low-mass dwarf galaxies
A tight correlation between the baryonic and observed acceleration of galaxies has been reported over a wide range of mass ($10^8 < M_{\rm bar}/{\rm M}_\odot < 10^{11}$) - the Radial Acceleration Rela...
arxiv.org
October 9, 2025 at 8:55 AM
Paper day! My PhD student Mariana Júlio, with @readdark.bsky.social, @pengfeili.bsky.social and others, studies the internal dynamics of dwarf galaxies and finds they don't agree with the Radial Acceleration Relation, challenging the dark matter alternative MOND.
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
4MOST’s social media account is live! First light expected on October 21st! (1pm UK time) 🔭🧪
Welcome to the official 4-metre Multi-Object Spectroscopic Telescope (4MOST) Bluesky account! Stay tuned for our first-light events coming very soon, and updates on all of the amazing science we will be completing over the years to come!
📷: Y. Beletsky/ESO
#4most #ESO #telescope #astronomy
📷: Y. Beletsky/ESO
#4most #ESO #telescope #astronomy
September 30, 2025 at 12:57 PM
4MOST’s social media account is live! First light expected on October 21st! (1pm UK time) 🔭🧪
Reposted by Denis Erkal
Let us name those who should take responsibility for this situation. The senior management of universities failed to negotiate a sustainable system of funding, and then sleep-walked into mess.
But will they be held accountable? Of course not.
www.theguardian.com/education/20...
But will they be held accountable? Of course not.
www.theguardian.com/education/20...
Quarter of UK university physics departments at risk of closing, survey finds
Four out of five making staff cuts as physicists say findings are ‘great concern’ for UK’s leadership in important areas
www.theguardian.com
September 20, 2025 at 6:13 AM
Let us name those who should take responsibility for this situation. The senior management of universities failed to negotiate a sustainable system of funding, and then sleep-walked into mess.
But will they be held accountable? Of course not.
www.theguardian.com/education/20...
But will they be held accountable? Of course not.
www.theguardian.com/education/20...
Here’s the Cygnus loop with a Seestar S50. It’s so big that one mosaic won’t fit it so I stitched two of them together. The total exposure is about 4 hours. It would be cool to go even wider and deeper. 🔭
August 22, 2025 at 7:56 PM
Here’s the Cygnus loop with a Seestar S50. It’s so big that one mosaic won’t fit it so I stitched two of them together. The total exposure is about 4 hours. It would be cool to go even wider and deeper. 🔭
Reposted by Denis Erkal
August 17, 2025 at 10:22 PM
Reposted by Denis Erkal
Stranded in Italy thanks to Air Canada. They say by email that they can't find any flights in the next three days and offer a refund -- ignoring EU 261/2004 regulations that they have to rebook on *any* airline. They do not answer the phone.
AC has absolute contempt for its customers and employees.
AC has absolute contempt for its customers and employees.
August 17, 2025 at 9:55 PM
Stranded in Italy thanks to Air Canada. They say by email that they can't find any flights in the next three days and offer a refund -- ignoring EU 261/2004 regulations that they have to rebook on *any* airline. They do not answer the phone.
AC has absolute contempt for its customers and employees.
AC has absolute contempt for its customers and employees.
Reposted by Denis Erkal
Episode 17 has dropped! Tune in to hear Payel & Michelle talk about about a dark matter subhalo detection, the problem(s) with super massive black holes, massive star clusters in the Sparkler, speedy white dwarfs and more! 🔭☄️ starxiv.com/2025/08/04/e...
August 4, 2025 at 7:00 AM
Episode 17 has dropped! Tune in to hear Payel & Michelle talk about about a dark matter subhalo detection, the problem(s) with super massive black holes, massive star clusters in the Sparkler, speedy white dwarfs and more! 🔭☄️ starxiv.com/2025/08/04/e...
Anyone else notice any weird unit issues with Google lately? (3e19 m)/(1 kpc) gives 55.7 instead of ~1. Not good if you like using Google for quick unit conversions 🔭
July 24, 2025 at 8:18 PM
Anyone else notice any weird unit issues with Google lately? (3e19 m)/(1 kpc) gives 55.7 instead of ~1. Not good if you like using Google for quick unit conversions 🔭
Reposted by Denis Erkal
New potential interstellar object in the South: 168 hr arc but e already 9+/-1. H=11.
Follow-up encouraged! 🔭
Follow-up encouraged! 🔭
Scout: NEOCP Hazard Assessment
NASA's Near-Earth Object (NEO) web-site. Data related to Earth impact risk, close-approaches, and much more.
cneos.jpl.nasa.gov
July 2, 2025 at 3:32 AM
New potential interstellar object in the South: 168 hr arc but e already 9+/-1. H=11.
Follow-up encouraged! 🔭
Follow-up encouraged! 🔭
Reposted by Denis Erkal
Non-hot take: The "AI will kill us" discourse was a distraction from the real problem: it removes the young end of the skilled knowledge workforce. They are harder to train, because AI can do it for them. They can't get jobs, because AI can do it for their bosses. www.theguardian.com/business/202...
Number of new UK entry-level jobs has dived since ChatGPT launch – research
Vacancies for graduate jobs, apprenticeships, internships and junior jobs with no degree requirement have dropped 32%, Adzuna finds
www.theguardian.com
June 30, 2025 at 1:59 PM
Non-hot take: The "AI will kill us" discourse was a distraction from the real problem: it removes the young end of the skilled knowledge workforce. They are harder to train, because AI can do it for them. They can't get jobs, because AI can do it for their bosses. www.theguardian.com/business/202...
Come join us at Surrey! Please get in touch with questions on any of the fellowships (junior to senior), and if you're interested but not sure what you're eligible for, contact me. 🔭
If you want to join our wonderful astrophysics research group here at Surrey, please get in touch with @derkal.bsky.social!
Considering a senior UK fellowship (ERF, URF)? We have a great group at Surrey and our internal deadline for the ERF is July 8th. We are looking for a light-touch application: CV and 1 page research statement. I'm the contact person, so send questions/material to me
www.ukri.org/what-we-do/d... 🔭
www.ukri.org/what-we-do/d... 🔭
June 26, 2025 at 10:22 AM
Come join us at Surrey! Please get in touch with questions on any of the fellowships (junior to senior), and if you're interested but not sure what you're eligible for, contact me. 🔭
Wow, look at that increase in depth!
My mind is absolutely blown by these stellar halos nearby NGC 4364!
Left: DESI Legacy Imaging Surveys (DR10)
Right: Newly released @vrubinobs.bsky.social imaging!!!
#AstroSci 🧪🔭
Left: DESI Legacy Imaging Surveys (DR10)
Right: Newly released @vrubinobs.bsky.social imaging!!!
#AstroSci 🧪🔭
June 23, 2025 at 7:00 PM
Wow, look at that increase in depth!
Reposted by Denis Erkal
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 4:06 AM
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
Considering a senior UK fellowship (ERF, URF)? We have a great group at Surrey and our internal deadline for the ERF is July 8th. We are looking for a light-touch application: CV and 1 page research statement. I'm the contact person, so send questions/material to me
www.ukri.org/what-we-do/d... 🔭
www.ukri.org/what-we-do/d... 🔭
Ernest Rutherford Fellowships
Ernest Rutherford Fellowships (ERF) enables early career researchers with clear leadership potential to establish a strong, independent research programme. They encourage talented researchers in UK un...
www.ukri.org
June 17, 2025 at 10:21 AM
Considering a senior UK fellowship (ERF, URF)? We have a great group at Surrey and our internal deadline for the ERF is July 8th. We are looking for a light-touch application: CV and 1 page research statement. I'm the contact person, so send questions/material to me
www.ukri.org/what-we-do/d... 🔭
www.ukri.org/what-we-do/d... 🔭
Really good set of slides about how Nazi scientists did very little to combat the Nazi party
In light of this deeply illegal activity at NSF and the ongoing attack on American science, I'm posting the slides from my 2017 talk at the American Physical Society about the Nazi take over of German physics/why German is no longer science's lingua franca 🧪
🧵 1/26
drive.google.com/file/d/1_MCm...
🧵 1/26
drive.google.com/file/d/1_MCm...
May 31, 2025 at 11:16 PM
Really good set of slides about how Nazi scientists did very little to combat the Nazi party
Reposted by Denis Erkal
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 3:24 AM
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... 🔭 🧪
Reposted by Denis Erkal
Bullying at Cambridge University
There's a long article in today's Observer about bullying at Cambridge University, which I encourage you to read, as it shows that the scale of the bullying problem in Cambridge is very worrying. I'll just emphasize a couple of things here. One is that Cambridge…
There's a long article in today's Observer about bullying at Cambridge University, which I encourage you to read, as it shows that the scale of the bullying problem in Cambridge is very worrying. I'll just emphasize a couple of things here. One is that Cambridge…
Bullying at Cambridge University
There's a long article in today's Observer about bullying at Cambridge University, which I encourage you to read, as it shows that the scale of the bullying problem in Cambridge is very worrying. I'll just emphasize a couple of things here. One is that Cambridge University is due to elect a new Chancellor this year and, as is mentioned in the Observer, Professor Wyn Evans of the Institute of Astronomy is planning to stand as a candidate on an anti-bullying platform.
telescoper.blog
April 13, 2025 at 10:37 AM
Bullying at Cambridge University
There's a long article in today's Observer about bullying at Cambridge University, which I encourage you to read, as it shows that the scale of the bullying problem in Cambridge is very worrying. I'll just emphasize a couple of things here. One is that Cambridge…
There's a long article in today's Observer about bullying at Cambridge University, which I encourage you to read, as it shows that the scale of the bullying problem in Cambridge is very worrying. I'll just emphasize a couple of things here. One is that Cambridge…
I tried to image the Palomar 5 globular cluster with a Seestar S50 for 3 hours. The cluster is the middle of this image and some of the faintest stars have Gaia G mags of ~17.5 and the right proper motions to be Pal 5 stars. 🔭
April 12, 2025 at 1:44 PM
I tried to image the Palomar 5 globular cluster with a Seestar S50 for 3 hours. The cluster is the middle of this image and some of the faintest stars have Gaia G mags of ~17.5 and the right proper motions to be Pal 5 stars. 🔭
Great book review by @chanda.bsky.social about another disappointing physicist, Roger Penrose, who didn’t treat their family or female students well.
NEW WRITING ✍🏽
The most shocking book I’ve read in years was … a biography of theoretical physicist Roger Penrose 🫠
I reviewed it for @physicsworld.bsky.social. Prepare yourselves 😭
#BookSky #scicomm ⚛️ 🧪
physicsworld.com/a/so-you-thi...
The most shocking book I’ve read in years was … a biography of theoretical physicist Roger Penrose 🫠
I reviewed it for @physicsworld.bsky.social. Prepare yourselves 😭
#BookSky #scicomm ⚛️ 🧪
physicsworld.com/a/so-you-thi...
So you think you know Roger Penrose? Be prepared to be shocked – Physics World
Chanda Prescod-Weinstein reviews The Impossible Man: Roger Penrose and the Cost of Genius by Patchen Barss
physicsworld.com
April 4, 2025 at 8:35 AM
Great book review by @chanda.bsky.social about another disappointing physicist, Roger Penrose, who didn’t treat their family or female students well.
Spent 4 hours on NGC 4631 (top galaxy, aka Whale galaxy) and NGC 4656 (bottom galaxy, aka Hockey stick galaxy) with a seestar last night. The hook in NGC 4656 is due to an interaction with other galaxies in the group. 🔭
March 31, 2025 at 8:15 AM
Spent 4 hours on NGC 4631 (top galaxy, aka Whale galaxy) and NGC 4656 (bottom galaxy, aka Hockey stick galaxy) with a seestar last night. The hook in NGC 4656 is due to an interaction with other galaxies in the group. 🔭
Today’s solar eclipse from the southern UK. It was taken with a seestar 50. I was very impressed how well it kept the sun centered in the timelapse! 🔭
youtube.com/shorts/f-wsa...
youtube.com/shorts/f-wsa...
March 29, 2025 at 12:38 PM
Today’s solar eclipse from the southern UK. It was taken with a seestar 50. I was very impressed how well it kept the sun centered in the timelapse! 🔭
youtube.com/shorts/f-wsa...
youtube.com/shorts/f-wsa...
Reposting to 🔭
Denis Erkal (@derkal.bsky.social), one of our contributors, is an expert in galaxy modeling at the @uniofsurrey.bsky.social
He has given a talk focused on the Milky Way’s formation and dark matter properties 🌌
#ARRAKIHS #GalaxyModels #DarkMatter #MilkyWay
He has given a talk focused on the Milky Way’s formation and dark matter properties 🌌
#ARRAKIHS #GalaxyModels #DarkMatter #MilkyWay
March 29, 2025 at 10:11 AM
Reposting to 🔭
Reposted by Denis Erkal
Denis Erkal (@derkal.bsky.social), one of our contributors, is an expert in galaxy modeling at the @uniofsurrey.bsky.social
He has given a talk focused on the Milky Way’s formation and dark matter properties 🌌
#ARRAKIHS #GalaxyModels #DarkMatter #MilkyWay
He has given a talk focused on the Milky Way’s formation and dark matter properties 🌌
#ARRAKIHS #GalaxyModels #DarkMatter #MilkyWay
March 28, 2025 at 12:53 PM
Denis Erkal (@derkal.bsky.social), one of our contributors, is an expert in galaxy modeling at the @uniofsurrey.bsky.social
He has given a talk focused on the Milky Way’s formation and dark matter properties 🌌
#ARRAKIHS #GalaxyModels #DarkMatter #MilkyWay
He has given a talk focused on the Milky Way’s formation and dark matter properties 🌌
#ARRAKIHS #GalaxyModels #DarkMatter #MilkyWay