Hi all,
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Someone from Saji Observatory reported a possible fragment 4.5 arcseconds south of C/2024 G3, detected with a 103 cm telescope. Can somebody confirm?
https://x.com/sajiastropark/status/1878267812893913493
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K
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I was processing some FITS images and I saw additional tail in C3 Orange filter, which is really faint in images taken without any filters. Is it ordinary tail or a sodium tail?
Best regards
(I have some screenshots but electricity ran out and I'll send them when it comes back) Temat: Re: [comets-ml] C/2024 G3 (ATLAS) Data: 2025-01-12 10:06 Nadawca: "Maik Meyer" <maik@...> Adresat: [email protected];
The magnitudes I see this morning definitely mean that a visual daytime sighting today will be impossible. Since the maximum should happen over the coming 48 hours the question will be if it reaches -4 mag or brighter on the 13th or 14th. Assuming that it is -1.5 this morning I think this won't be possible if the comet behaves normally.
Maik
Sent from my mobile
11.01.2025 19:20:56 Nick James <comets@...>:
Maik,
Good luck tomorrow. I know you are very experienced but be careful. I'm only risking a camera, not my eyes!
I've processed the full video now and the result is here:
https://britastro.org/observations/observation.php?id=20250111_181128_a9e9cf292d6b6418
I've tried to estimate the magnitude by measuring the intensity in a 40 arcsec diameter aperture and comparing it to a video of Venus taken just before the comet observation using the same settings. Assuming Venus is -4.6 and using a correction of 1.0 mag for differential altitude (Venus was at 29 deg, the comet at 10 deg) I get -0.8. That doesn't really seem bright enough given how prominent the comet is on the image but that is what I get!
Nick.
On 11/01/2025 15:15, Maik Meyer wrote:
Nick,
this is really great, great images, thank you. I might try it visually tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in the next 24-48 hours.
Maik
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The magnitudes I see this morning definitely mean that a visual daytime sighting today will be impossible. Since the maximum should happen over the coming 48 hours the question will be if it reaches -4 mag or brighter on the 13th or 14th. Assuming that it is -1.5 this morning I think this won't be possible if the comet behaves normally.
Maik
Sent from my mobile
11.01.2025 19:20:56 Nick James <comets@...>:
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Maik,
Good luck tomorrow. I know you are very experienced but be careful. I'm only risking a camera, not my eyes!
I've processed the full video now and the result is here:
https://britastro.org/observations/observation.php?id=20250111_181128_a9e9cf292d6b6418
I've tried to estimate the magnitude by measuring the intensity in a 40 arcsec diameter aperture and comparing it to a video of Venus taken just before the comet observation using the same settings. Assuming Venus is -4.6 and using a correction of 1.0 mag for differential altitude (Venus was at 29 deg, the comet at 10 deg) I get -0.8. That doesn't really seem bright enough given how prominent the comet is on the image but that is what I get!
Nick.
On 11/01/2025 15:15, Maik Meyer wrote:
Nick,
this is really great, great images, thank you. I might try it visually tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in the next 24-48 hours.
Maik
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Nick, that's an excellent image and I very much trust the brightness estimates
from you and Qicheng.
Don Pettit's beautiful image from space might not be appropriate to compare the
brightness of mercury and the comet as both of them might well be saturated
with mercury at much larger amount. In this case the larger extent of the
head of the comet in comparison to the (point-like) planet only gives an
illusion of much brighter appearance.
Thomas
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Am Sat, 11 Jan 2025 20:21:51 +0000 (UTC)
schrieb "Qicheng Zhang via groups.io" <qzalaska@...>:
I also just took a very quick look at the short exposure (minimally saturated) LASCO C3 data as well from Jan 11 ~12 UT. It's not possible to isolate the brightness of the coma alone, as that's <1 px in size in this camera, but within a 7 px ~ 6.5 arcmin diameter aperture, it was at V mag ~ -1.3. Note that the comet is now passing behind the (out of focus) pylon that holds the occulter in place, and the vignetting by this pylon is causing the saturation spikes in the synoptic C3 Clear data to shrink (i.e., the comet itself is not fading despite becoming less saturated on the detector).
Qicheng
On Saturday, January 11, 2025 at 11:33:02 a.m. MST, Qicheng Zhang via groups.io <qzalaska@...> wrote:
That's consistent with my initial crude estimate this morning of -0.5 (measured against Mercury earlier at a similar airmass). The comet's easy visibility is because its coma is so compact, giving it a very high surface brightness now already comparable to C/2023 A3 at its peak.
Qicheng
On Saturday, January 11, 2025 at 11:20:52 a.m. MST, Nick James <comets@...> wrote:
Maik,
Good luck tomorrow. I know you are very experienced but be careful. I'm
only risking a camera, not my eyes!
I've processed the full video now and the result is here:
I've tried to estimate the magnitude by measuring the intensity in a 40
arcsec diameter aperture and comparing it to a video of Venus taken just
before the comet observation using the same settings. Assuming Venus is
-4.6 and using a correction of 1.0 mag for differential altitude (Venus
was at 29 deg, the comet at 10 deg) I get -0.8. That doesn't really seem
bright enough given how prominent the comet is on the image but that is
what I get!
Nick.
On 11/01/2025 15:15, Maik Meyer wrote:
Nick,
this is really great, great images, thank you. I might try it visually
tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in
the next 24-48 hours.
Maik
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ATLAS from the ISS, was Re: C/2024 G3 (ATLAS) from ISS
The version on Reddit had more dynamic; I could get out of it. And the later Pettit image - further processed in - reveals even more tail structure. Both of his images show two dots left and right of the comet's head: ghosts created by the ISS window? Then the central condensation would be reeeeally bright! Also of note: the great day-time image from Japan this morning ... and this 2 1/2 days before perihelion.
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Daniel
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Gesendet: Samstag, 11. Januar 2025 um 20:42
Von: "Matson, Rob D. via groups.io" <robert.d.matson@...>
Betreff: [comets-ml] C/2024 G3 (ATLAS) from ISS
Hi All: Here’s Don Pettit’s image from January 9th at 12:59 UT. Clearly the comet was far, far brighter at that time than Mercury (mv -0.4) to its lower left.?
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I also just took a very quick look at the short exposure (minimally saturated) LASCO C3 data as well from Jan 11 ~12 UT. It's not possible to isolate the brightness of the coma alone, as that's <1 px in size in this camera, but within a 7 px ~ 6.5 arcmin diameter aperture, it was at V mag ~ -1.3. Note that the comet is now passing behind the (out of focus) pylon that holds the occulter in place, and the vignetting by this pylon is causing the saturation spikes in the synoptic C3 Clear data to shrink (i.e., the comet itself is not fading despite becoming less saturated on the detector).
Qicheng
On Saturday, January 11, 2025 at 11:33:02 a.m. MST, Qicheng Zhang via groups.io <qzalaska@...> wrote:
That's consistent with my initial crude estimate this morning of -0.5 (measured against Mercury earlier at a similar airmass). The comet's easy visibility is because its coma is so compact, giving it a very high surface brightness now already comparable to C/2023 A3 at its peak.
Qicheng
On Saturday, January 11, 2025 at 11:20:52 a.m. MST, Nick James <comets@...> wrote:
Maik,
Good luck tomorrow. I know you are very experienced but be careful. I'm
only risking a camera, not my eyes!
I've processed the full video now and the result is here:
I've tried to estimate the magnitude by measuring the intensity in a 40
arcsec diameter aperture and comparing it to a video of Venus taken just
before the comet observation using the same settings. Assuming Venus is
-4.6 and using a correction of 1.0 mag for differential altitude (Venus
was at 29 deg, the comet at 10 deg) I get -0.8. That doesn't really seem
bright enough given how prominent the comet is on the image but that is
what I get!
Nick.
On 11/01/2025 15:15, Maik Meyer wrote: > Nick, > > this is really great, great images, thank you. I might try it visually > tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in > the next 24-48 hours. > > Maik
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C/2024 G3 (ATLAS) from ISS
Hi All: Here’s Don Pettit’s image from January 9th at 12:59 UT. Clearly the comet was far, far brighter at that time than Mercury (mv -0.4) to its lower left.? --Rob
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That's consistent with my initial crude estimate this morning of -0.5 (measured against Mercury earlier at a similar airmass). The comet's easy visibility is because its coma is so compact, giving it a very high surface brightness now already comparable to C/2023 A3 at its peak.
Qicheng
On Saturday, January 11, 2025 at 11:20:52 a.m. MST, Nick James <comets@...> wrote:
Maik,
Good luck tomorrow. I know you are very experienced but be careful. I'm
only risking a camera, not my eyes!
I've processed the full video now and the result is here:
I've tried to estimate the magnitude by measuring the intensity in a 40
arcsec diameter aperture and comparing it to a video of Venus taken just
before the comet observation using the same settings. Assuming Venus is
-4.6 and using a correction of 1.0 mag for differential altitude (Venus
was at 29 deg, the comet at 10 deg) I get -0.8. That doesn't really seem
bright enough given how prominent the comet is on the image but that is
what I get!
Nick.
On 11/01/2025 15:15, Maik Meyer wrote:
> Nick,
>
> this is really great, great images, thank you. I might try it visually
> tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in
> the next 24-48 hours.
>
> Maik
|
Maik,
Good luck tomorrow. I know you are very experienced but be careful. I'm only risking a camera, not my eyes!
I've processed the full video now and the result is here:
I've tried to estimate the magnitude by measuring the intensity in a 40 arcsec diameter aperture and comparing it to a video of Venus taken just before the comet observation using the same settings. Assuming Venus is -4.6 and using a correction of 1.0 mag for differential altitude (Venus was at 29 deg, the comet at 10 deg) I get -0.8. That doesn't really seem bright enough given how prominent the comet is on the image but that is what I get!
Nick.
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On 11/01/2025 15:15, Maik Meyer wrote: Nick,
this is really great, great images, thank you. I might try it visually tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in the next 24-48 hours.
Maik
|
Nick,
this is really great, great images, thank you. I might try it visually tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in the next 24-48 hours.
Maik
--
"One cannot discover comets lying in bed." * Lewis Swift
________________________________________________________________________
*** @skymorph.bsky.social
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Sorry, forgot to include details. The image was taken at 1432 UTC on 2025-01-11. At that time both comet and sun were 10 deg above my horizon.
Nick.
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On 11/01/2025 15:02, Nick James wrote: I've just managed to image C/2024 G3 (ATLAS) in daylight from Chelmsford, UK (latitude 51.5N) using a 90mm refractor and an ASI1600 camera. The attached image is a differenced stack of two lots of 20x700us frames offset in declination by 23 arcmin. You can see two versions of the comet, one in positive and one in negative. The orientation is N up and the elongation is currently 7.9 deg.
The sun and comet were both low down and the sky rather hazy so I was surprised to get such a strong image. The comet must be pretty bright. I have images of Venus taken with the same settings just before so I should be able to estimate the magnitude with an appropriate correction for the different altutude.
Nick.
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I've just managed to image C/2024 G3 (ATLAS) in daylight from Chelmsford, UK (latitude 51.5N) using a 90mm refractor and an ASI1600 camera. The attached image is a differenced stack of two lots of 20x700us frames offset in declination by 23 arcmin. You can see two versions of the comet, one in positive and one in negative. The orientation is N up and the elongation is currently 7.9 deg.
The sun and comet were both low down and the sky rather hazy so I was surprised to get such a strong image. The comet must be pretty bright. I have images of Venus taken with the same settings just before so I should be able to estimate the magnitude with an appropriate correction for the different altutude.
Nick.
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Hi Adrien/all
I reported astrometry of this comet on 2024112 from MPC Code I81 Tarbatness,however on investigation by Hirohisa Sato of the Comet Section of Oriental Astronomical Association (OAA) it turned out the the comet had been coincident with starUSNO-B1.0 1247-0142281 at mag 17.2 at the time of my observations. So the observations and astrometry are erroneous and should be deleted. Kacper Wierzchoz has been informed of this also. I did not make any detection of this comet on 20241124.I am giving this information in case any other investigator is looking at the available astrometry.
Denis Buczynski MPC I81
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------ Original Message ------ From: adrien.coffinet2@... To: [email protected] Sent: Friday, January 10th 2025, 15:21 Subject: [comets-ml] P/2024 S2 (Rankin) Hi all, CBET 5492 reports on the likely desintegration of P/2024 S2 (Rankin) www.cbat.eps.harvard.edu/iau/cbet/005400/CBET005492.txt . Adrien
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Hi all,
CBET 5492 reports on the likely desintegration of P/2024 S2 (Rankin)
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If it sticks to 7.1 + 11.7 log r it will be around -2. It is likely to be within a magnitude of that.
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Regards,
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Jonathan Shanklin
BAA Comet Section visual observations co-ordinator
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From: [email protected] <[email protected]>
On Behalf Of Matson, Rob D. via groups.io
Sent: Thursday, January 9, 2025 10:25 PM
To: [email protected]
Subject: [comets-ml] C/2024 G3 (ATLAS)
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Hi All: Astronaut Don Pettit captured a nice image of C/2024 G3 (ATLAS) from ISS earlier today prior to one of his local sunrises. At the time of his shot (1/9 12:59 UT, Nikon Z9 lens, f/1.2, 1/60th of second)
the solar elongation was only 11 degrees. I’ll ask Don if I can share it here. Any estimate of how bright it should be right now? There are Sagittarius reference stars in his image (mu, lambda, phi, delta, gamma, eta) plus Mercury and it is far brighter than
any of them. (Mercury currently -0.4, and the comet looks at least 2 or 3 magnitudes brighter).? --Rob
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Hi Terry -- I put in a request to Don to see if he can provide a raw image or images for photometry... --Rob
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of terryjlovejoy via groups.io Sent: Thursday, January 9, 2025 2:30 PM To: [email protected]Subject: EXTERNAL: Re: [comets-ml] C/2024 G3 (ATLAS) CAUTION: This email originated from outside of Leidos. Be cautious when clicking or opening content. Hi Rob, Can you ask him if he can take/share some raw images so we can do some photometric measurements? It was about mag 0, although when I observed it on Jan 8 18:40 UT it seemed to have faded just slightly. Terry On Friday 10 January 2025 at 08:24:54 am AEST, Matson, Rob D. via groups.io <robert.d.matson@...> wrote: Hi All: Astronaut Don Pettit captured a nice image of C/2024 G3 (ATLAS) from ISS earlier today prior to one of his local sunrises. At the time of his shot (1/9 12:59 UT, Nikon Z9 lens, f/1.2, 1/60th of second) the solar elongation was only 11 degrees. I’ll ask Don if I can share it here. Any estimate of how bright it should be right now? There are Sagittarius reference stars in his image (mu, lambda, phi, delta, gamma, eta) plus Mercury and it is far brighter than any of them. (Mercury currently -0.4, and the comet looks at least 2 or 3 magnitudes brighter). --Rob
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Rob,
COBS is a good source of info on comet magnitudes:
As Terry says, the latest ground based observations have it around zero. Having the raw files from Don would be great if possible so we could do some photometry.
Nick.
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On 09/01/2025 22:24, Matson, Rob D. via groups.io wrote: Hi All: Astronaut Don Pettit captured a nice image of C/2024 G3 (ATLAS) from ISS earlier today prior to one of his local sunrises. At the time of his shot (1/9 12:59 UT, Nikon Z9 lens, f/1.2, 1/60th of second) the solar elongation was only 11 degrees. I'll ask Don if I can share it here. Any estimate of how bright it should be right now? There are Sagittarius reference stars in his image (mu, lambda, phi, delta, gamma, eta) plus Mercury and it is far brighter than any of them. (Mercury currently -0.4, and the comet looks at least 2 or 3 magnitudes brighter). --Rob
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Hi Rob,
Can you ask him if he can take/share some raw images so we can do some photometric measurements?
It was about mag 0, although when I observed it on Jan 8 18:40 UT it seemed to have faded just slightly.
Terry
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On Friday 10 January 2025 at 08:24:54 am AEST, Matson, Rob D. via groups.io <robert.d.matson@...> wrote:
??
Hi All: Astronaut Don Pettit captured a nice image of C/2024 G3 (ATLAS) from ISS earlier today prior to one of his local sunrises. At the time of his shot (1/9 12:59 UT, Nikon Z9 lens, f/1.2, 1/60th of second) the solar elongation was only 11 degrees. I’ll ask Don if I can share it here. Any estimate of how bright it should be right now? There are Sagittarius reference stars in his image (mu, lambda, phi, delta, gamma, eta) plus Mercury and it is far brighter than any of them. (Mercury currently -0.4, and the comet looks at least 2 or 3 magnitudes brighter).? --Rob
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Hi All: Astronaut Don Pettit captured a nice image of C/2024 G3 (ATLAS) from ISS earlier today prior to one of his local sunrises. At the time of his shot (1/9 12:59 UT, Nikon Z9 lens, f/1.2, 1/60th of second) the solar elongation
was only 11 degrees. I’ll ask Don if I can share it here. Any estimate of how bright it should be right now? There are Sagittarius reference stars in his image (mu, lambda, phi, delta, gamma, eta) plus Mercury and it is far brighter than any of them. (Mercury
currently -0.4, and the comet looks at least 2 or 3 magnitudes brighter).? --Rob
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K. Ly
Denis Buczynski