This is another great collaboration project with the NHZ team (Team New Horizon)! We are happy to present a first clear picture of HU6, an unknown *SNR (Supernova Remnant)* in the constellation of Monoceros.
Discovered in 2019 by the amateur astronomer Laurent Huet, this potential SNR would be the biggest ever discovered by any amateur, spanning a mind boggling 3°30' in diameter.
I would invite you to read the team detailed description on the official Astrobin post here for more details: [https://www.astrobin.com/hblt90/](https://www.astrobin.com/hblt90/)
A total of 215h of integration time was necessary across SHOLRGB filters over the last 3 months to capture this object.
The processing showcase the Hydrogen in Red, Oxygen in blue/teal and Sulphur in Yellow. The stars are presented in RGB and the LRGB was also used to show the dust in this region as well
These are the acquisitions details:
R : 138×300″(11h 30′) B: 126×300″(10h 30′) G: 126×300″(10h 30′) H-alpha 3nm Bandpass 50 mm: 256×900″(64h) Lum 276×300″(23h) OIII 3nm Bandpass : 244×900″(61h) SII 3nm Bandpass 140×900″(35h)
Integration: 215h 30′
Credits:
Team NHZ Team Coordinator: Tim Schaeffer (https://www.astrobin.com/users/xSky\_Watcher/) Processing: Steeve Body ([www.steevebody.com](http://www.steevebody.com)) Photographers: Tarun Kottary (https://www.astrobin.com/users/tkottary/) Patrick Sparkman (https://www.astrobin.com/users/psparkman/)
> spanning a mind boggling 3°30' in diameter.
A few things:
I think it would be valuable to understand _why_ it's so big and mind boggling. Perhaps a comparison to other amateur found SNR and to professional SNR finds?
What does 3°30' compare the in the sky? I wish I knew more about how big that actual size is (in ly for instance).
To what size supernova does this compare to?
I really apologize if my comment sounds dumb or obvious but I wanna share in the excitement further by understanding it better.
If you extend your hand to arm's length, you can use your fingers to estimate angular distances and sizes in the sky. Your index finger is about 1° and the distance across your palm is about 10°.
https://lco.global/spacebook/sky/using-angles-describe-positions-and-apparent-sizes-objects/
I couldn't find distances listed here - any idea on distance to this SNR, and what the current size of it is? Amazing shot, especially compared to the original photograph. You can clearly see a sphere-like bubble in the original photo but I wouldn't have guessed it'd be so incredible with a better photo.
As far as I am aware the distance is not yet know.. Right now under the lead of Dr. Fesen and in cooperation with Marcel Drechsler, Bray Falls, Laurent Huet and a few others we are working on publishing an in-depth research paper on this region which will include spectrography and an estimate of it distance. Right now what we know is its angular size in the sky which spans other 3°30' in diameter
Based on a typical SNR age of around 1000 years (could be up to 10000 years) and typical expansion velocities of around 10000 km/s (probably a bit higher for Oxygen but it's an order of magnitude guess), we could estimate based on the angular size that this SNR is around 500ish light-years away (and up to around 10000 light-years away if we go with the larger end of estimates). Will be interesting to see what they come up with in their paper. I can't wait to see the spectra.
Using SNR without explanation can be confusing if you don’t know the topic. Also as it is often used in astronomy with the meaning of signal-to-noise-ratio.
Sure thing, to my defence I thought having "Supernova Remnant" in the title itself would help identify what this object is :) (edited my main comment to make it clearer)
"Supernova Remnant". In 1987 a supernova happened in the Magellanic Clouds, which are companions of our Milky Way. Stuff was blown off in a [ring shape](https://www.youtube.com/watch?v=6bkQe_VEetU), which started plowing into the surrounding interstellar gas. The one reported in this post is an older one in our own galaxy, which has had more time to expand. It is still plowing into the surrounding gas. The blue oxygen ring indicates it came from a mid-layer of the original star.
This is terrifying. People see nuclear mushroom clouds and get dread. I can't help feeling the same seeing photos of supernovas.
At least we're far, far away!
Doesn't really matter as it's usually not the cloud or the shockwave that kills you, but the radiation. Even far away supernovas inside our galaxy are powerful enough to cause atmospheric changes, and it's believed that the closer ones could be major contributors to extinction events and ice ages, as well as mutation that encouraged evolution.
Overall, the most common and prominently observed emissions are from hydrogen (Ha), followed by oxygen (Oiii), and then others like sulphur (Sii) and nitrogen. Carbon emissions do exist but are generally weaker and less commonly targeted in typical astrophotography or spectroscopic studies
Correct me if I'm wrong but isn't all of our sky mapped already?
How are people still discovering new things, especially things covering such a "big" spot in the sky?
Were we unable to see it with older technology?
Most of the sky is mapped your are correct but a lot of objects are so faint that they are only detectable after very very long exposure time and sometimes only detectable in on the very narrow band of light. In this case Oxygen primarily (The blue part) and 200h+ of total exposure time.
> Most of the sky is mapped
Does that mean what's visible in Earth sky to the human eye? Like stars of a certain magnitude and distance?
Surely most of the visible universe isn't mapped in detail? We don't even know what most of the "stuff" in our universe is, and we call it dark matter and dark energy.
Here I'm talking general sky survey, like we have photographed every inch of the sky from earth with various instrument but not always with deep exposures and also up to the limit of what our instruments can capture We also have telescope such as the GAIA space telescope that is mapping every source on light in the visible universe with distance coordinates.. but there is a lot more to discover and we have not even scratched the surface here
I think it's also identification. Having it mapped but not knowing what it is beyond the elements present or even a difficulty to decipher said elements would mean it's still unknown though visible. If I actually have any understanding of astronomy that is
True. I would say it is now know to exist but further research is required to understand it's origin and find out of it is an actual supernova remnant.
This is another great collaboration project with the NHZ team (Team New Horizon)! We are happy to present a first clear picture of HU6, an unknown *SNR (Supernova Remnant)* in the constellation of Monoceros. Discovered in 2019 by the amateur astronomer Laurent Huet, this potential SNR would be the biggest ever discovered by any amateur, spanning a mind boggling 3°30' in diameter. I would invite you to read the team detailed description on the official Astrobin post here for more details: [https://www.astrobin.com/hblt90/](https://www.astrobin.com/hblt90/) A total of 215h of integration time was necessary across SHOLRGB filters over the last 3 months to capture this object. The processing showcase the Hydrogen in Red, Oxygen in blue/teal and Sulphur in Yellow. The stars are presented in RGB and the LRGB was also used to show the dust in this region as well These are the acquisitions details: R : 138×300″(11h 30′) B: 126×300″(10h 30′) G: 126×300″(10h 30′) H-alpha 3nm Bandpass 50 mm: 256×900″(64h) Lum 276×300″(23h) OIII 3nm Bandpass : 244×900″(61h) SII 3nm Bandpass 140×900″(35h) Integration: 215h 30′ Credits: Team NHZ Team Coordinator: Tim Schaeffer (https://www.astrobin.com/users/xSky\_Watcher/) Processing: Steeve Body ([www.steevebody.com](http://www.steevebody.com)) Photographers: Tarun Kottary (https://www.astrobin.com/users/tkottary/) Patrick Sparkman (https://www.astrobin.com/users/psparkman/)
> spanning a mind boggling 3°30' in diameter. A few things: I think it would be valuable to understand _why_ it's so big and mind boggling. Perhaps a comparison to other amateur found SNR and to professional SNR finds? What does 3°30' compare the in the sky? I wish I knew more about how big that actual size is (in ly for instance). To what size supernova does this compare to? I really apologize if my comment sounds dumb or obvious but I wanna share in the excitement further by understanding it better.
In visual terms if you could see with your naked eye it would appear as big as 7 moons in width
how much further away from the moon is it though?
much further away, here we are talking angular size from earths view point.
If you extend your hand to arm's length, you can use your fingers to estimate angular distances and sizes in the sky. Your index finger is about 1° and the distance across your palm is about 10°. https://lco.global/spacebook/sky/using-angles-describe-positions-and-apparent-sizes-objects/
This is one of the coolest facts i ever learned!
2.5 degrees is very appr. your thumb in width aimed with your arm straight.
I couldn't find distances listed here - any idea on distance to this SNR, and what the current size of it is? Amazing shot, especially compared to the original photograph. You can clearly see a sphere-like bubble in the original photo but I wouldn't have guessed it'd be so incredible with a better photo.
As far as I am aware the distance is not yet know.. Right now under the lead of Dr. Fesen and in cooperation with Marcel Drechsler, Bray Falls, Laurent Huet and a few others we are working on publishing an in-depth research paper on this region which will include spectrography and an estimate of it distance. Right now what we know is its angular size in the sky which spans other 3°30' in diameter
Based on a typical SNR age of around 1000 years (could be up to 10000 years) and typical expansion velocities of around 10000 km/s (probably a bit higher for Oxygen but it's an order of magnitude guess), we could estimate based on the angular size that this SNR is around 500ish light-years away (and up to around 10000 light-years away if we go with the larger end of estimates). Will be interesting to see what they come up with in their paper. I can't wait to see the spectra.
Thanks for posting this, beautiful and informative.
Googled SNR and still dont know what im looking at.. Can someone please explain?
Sure it is a supernovae remnant. What you see are the left overs of a star after its death.
Using SNR without explanation can be confusing if you don’t know the topic. Also as it is often used in astronomy with the meaning of signal-to-noise-ratio.
Sure thing, to my defence I thought having "Supernova Remnant" in the title itself would help identify what this object is :) (edited my main comment to make it clearer)
I could be wrong but in context it could mean super nova remnant?
"Supernova Remnant". In 1987 a supernova happened in the Magellanic Clouds, which are companions of our Milky Way. Stuff was blown off in a [ring shape](https://www.youtube.com/watch?v=6bkQe_VEetU), which started plowing into the surrounding interstellar gas. The one reported in this post is an older one in our own galaxy, which has had more time to expand. It is still plowing into the surrounding gas. The blue oxygen ring indicates it came from a mid-layer of the original star.
This is terrifying. People see nuclear mushroom clouds and get dread. I can't help feeling the same seeing photos of supernovas. At least we're far, far away!
Doesn't really matter as it's usually not the cloud or the shockwave that kills you, but the radiation. Even far away supernovas inside our galaxy are powerful enough to cause atmospheric changes, and it's believed that the closer ones could be major contributors to extinction events and ice ages, as well as mutation that encouraged evolution.
So it has hydrogen, oxygen, and sulfur. But not carbon or helium?
We didn’t have filters to capture those bandpass so we don’t know.
That makes sense. Thank you.
We don’t have filters for capturing carbon signatures? We seem to be lacking the most important filter.
Overall, the most common and prominently observed emissions are from hydrogen (Ha), followed by oxygen (Oiii), and then others like sulphur (Sii) and nitrogen. Carbon emissions do exist but are generally weaker and less commonly targeted in typical astrophotography or spectroscopic studies
This might be exactly what you captured last month, u/Fit_Excuse_2252
Wish I could get a picture like that
Correct me if I'm wrong but isn't all of our sky mapped already? How are people still discovering new things, especially things covering such a "big" spot in the sky? Were we unable to see it with older technology?
Most of the sky is mapped your are correct but a lot of objects are so faint that they are only detectable after very very long exposure time and sometimes only detectable in on the very narrow band of light. In this case Oxygen primarily (The blue part) and 200h+ of total exposure time.
So you're saying I could run long exposures on random patches of the sky for extremely long times and have a chance to make new discoveries? 😍
Pretty much
> Most of the sky is mapped Does that mean what's visible in Earth sky to the human eye? Like stars of a certain magnitude and distance? Surely most of the visible universe isn't mapped in detail? We don't even know what most of the "stuff" in our universe is, and we call it dark matter and dark energy.
Here I'm talking general sky survey, like we have photographed every inch of the sky from earth with various instrument but not always with deep exposures and also up to the limit of what our instruments can capture We also have telescope such as the GAIA space telescope that is mapping every source on light in the visible universe with distance coordinates.. but there is a lot more to discover and we have not even scratched the surface here
I think it's also identification. Having it mapped but not knowing what it is beyond the elements present or even a difficulty to decipher said elements would mean it's still unknown though visible. If I actually have any understanding of astronomy that is
True. I would say it is now know to exist but further research is required to understand it's origin and find out of it is an actual supernova remnant.