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Great capture Bill.
Things have certainly moved on from my one (and only) attempt at this nearly 20 years ago
http://www.threehillsobservatory.co.uk/astro/spectra_20.htmIt is interesting to try to compare Nick’s time lapse with what was seen at the same time from 400km further north, now archived at
http://threehillsobservatory.co.uk/allsky_camera/allsky_20241010_aurora.mp4
(South is to the left, west is up)
The short intense burst at ~21:02 corresponds to a bright band briefly appearing to the south in my camera and the other intense period ~23:15-23:35 coincides with when it shifted from north to overhead and south hereCheers
RobinThe weakness of the Swan band emission does confirm earlier observations that it is a carbon depleted comet eg
https://www.astronomerstelegram.org/?read=16637Cheers
RobinHi David,
What was the orientation of the slit relative to the comet? The sodium emission line is seen only on one side of the coma so presumably is from the sodium tail rather than any light pollution/atmospheric emission line
Cheers
RobinIf you zoom in you will find Comet 13P/Olbers
I had noticed that conjunction in CdC and wondered if anyone would get them in the same frame. Impressive image !
Robin
Be careful if using MELCHIORS spectra. I have studied a few and found two suspect spectra already so there may be more
HD205021B is the wrong star
HD180482 (22 Aql) has the wrong continuum shape
See
https://www.spectro-aras.com/forum/viewtopic.php?t=3148Cheers
RobinOh Dear, I see BBC Lead Weather Presenter Simon King is suggesting looking for the comet tonight “Around Sunset at 18:00-18:30 BST”.
https://www.bbc.co.uk/weather/articles/cq5e6jne670o
There is going to be a lot of disappointed people giving up at 18:30 when they could have had a nice view an hour later! There is a Twitter (x) link but I don’t use that. Anyone care to put him straight on this?Cheers
RobinAn ALPY200 spectrum from 20241010 (with severe auroral line contamination removed) confirms the typical features of a dwarf nova in outburst as described in ATel 16858
Cheers
RobinAttachments:
Clear here most of the night and spectacularly dynamic, particularly for about an hour around 23:00 UT. Captured on the all sky camera where the image to the north was saturated most of the time
http://www.threehillsobservatory.co.uk/allsky_camera/allsky_camera_page.htm
here is a single frame teaserCheers
RobinAttachments:
You can do it with a fixed mount using the natural sidereal motion to drift the sun across the slit as I experimented with here with my LHIRES
http://www.threehillsobservatory.co.uk/astro/spectra_29.htm
With Buil’s other instrument the SolEx, it is essentially a high resolution spectrograph which is mounted on a telescope and the mount is normally driven at x times sidereal, taking advantage of improvements in camera sensitivity and speed to reduce the scan time so the result is less reliant on stable conditions. The details of this device are yet to be revealed thoughSpectrum from 27th Sept
https://britastro.org/specdb/data_graph.php?obs_id=17144
very different from published spectra in quiescence eg
https://skyserver.sdss.org/dr17/en/get/SpecById.ashx?id=8671752135506155520Also picked up by MASTER yesterday at mag 13.6 (clear)
https://www.wis-tns.org/object/2024xhnThere is another PNV from 4 days ago around the same magnitude with no confirmation as yet
http://www.cbat.eps.harvard.edu/unconf/followups/J06393680+1604070.html
https://www.wis-tns.org/object/2024xdmA series of spectra by Peter Velez
https://www.spectro-aras.com/forum/viewtopic.php?t=3150Cheers
RobinThere is an interesting little “Muon Telescope” project here using 4 Geiger detectors in a coincidence detecting array
http://parac.eu/projectmk30.htmCheers
RobinBe interesting if there are spectra from around the same to see what’s happening there
The spectra in the ARAS database
https://aras-database.github.io/database/novavul2024.html
seem to suggest an overall drop in both continuum and H alpha from 20240828-20240907 with H alpha increasing slightly relative to the continuumCheers
RobinIf the spectra are too weak for ISIS to lock on to but overlay each other well in the combined image, you can just leave the fixed Y coordinate position box ticked. (My guiding takes care of the movement in Y so I normally operate this way)
Cheers
RobinIf you try ticking the fixed Y coordinate and sky not removed boxes and rerun the calibration, then click “display image” in the go tab, you will get the sum of your spectrum images with the binning zones overlaid so you can see what is happening. The objective is to have the spectra overlaying each other with the region
with the combined spectrum as narrow as possible. The spectrum binning zone should include all the spectrum region and the sky zones should include none of the spectrum region. If the spectra are not in the same Y position, with the fixed Y coordinate box unticked ISIS will attempt to track the Y movement and overlay them but as David says it may not lock onto faint spectra or with large movements between spectra.Cheers
RobinHi Stan,
The flare and time stamp on the image file name should be correct within a few seconds (2024-08-12 23:27:40 UTC) What time was your fireball ?
The camera takes 10 sec exposures per frame for fainter objects in the deeper sky rather than video for meteors but I am pretty sure what I saw was a satellite, not a fireball.
In the stretched images I can see the faint track for about 50 seconds before the flare, the flare lasted about 20 seconds and the track then continued as before the flare for at least another 10 seconds.
The animation is too big to post here but I have uploaded it to my website here.
http://threehillsobservatory.co.uk/allsky_camera/sat_flare_202408012T23_27_40_stretched.gif
The animation is 20x true speed. Each frame is a 10 second exposure, the yellow arrow marks the track in each image.Did any of the myriad of NEMATODE/GMN cameras in the south of the country pick up your fireball perhaps?
Cheers
Robin
