AT2024epj - A mag 10 transient in/near the LMC

Robin Leadbeater
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AT2024epj - A mag 10 transient in/near the LMC

Post by Robin Leadbeater »

04:55:03.766 -65:55:57.18
https://www.wis-tns.org/object/2024epj

Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
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2SPOT
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by 2SPOT »

Here's the spectrum taken last night from our 2SPOT eshel spectrograph from Chile.

Image


Very noisy at magnitude around V=10 and too low for an echelle spectrograph and a RC 12'.

Image

the two narrow emission line at 5577,35 Å and 6300 Å are [O I] atmospherics lines (not substract from the echelle spectrum)

And the full graph with a filter

Image

It seems to us that this is a novae, with an expansion velocity of the ejecta on the hydrogen lines about 4000km/s.

Image
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Tom Love
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by Tom Love »

And this is what I've managed with an Alpy. I suspect it's a little fainter than the 10th magnitude it has been estimated at. Similar result of about +/- 4200 km/s for the expanding shell.
Attachments
at2024epj_ 20240320_856_Tom Love.png
AT2024epj_HAlpha.png
AT2024epj_HAlpha.png (40.68 KiB) Viewed 2504 times
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Martinborough, New Zealand. Alpy, Lhires RC12
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by 2SPOT »

Great Tom !!!

We will try next night with our Alpy 600....
2SPOT : Southern Spectroscopic Project Observatory Team
Website : http://www.2spot.org - Observatory Site : Deep Sky Chile https://www.deepskychile.com/fr/
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Robin Leadbeater
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by Robin Leadbeater »

Tom Love wrote: Wed Mar 20, 2024 12:36 pm And this is what I've managed with an Alpy. I suspect it's a little fainter than the 10th magnitude it has been estimated at. Similar result of about +/- 4200 km/s for the expanding shell.
Yes the latest report on TNS suggests it is fading rapidly

2024-03-18 18:34:24.000 11.56 (sloan g)

Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
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Francois Teyssier
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by Francois Teyssier »

Good result despite the low luminosity

Very fast nova.
Expansion velocity 4900-5100 km/s measured on H alpha and H beta.

Page opened: https://aras-database.github.io/database/at2024epj.html
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by 2SPOT »

2SPOT : Southern Spectroscopic Project Observatory Team
Website : http://www.2spot.org - Observatory Site : Deep Sky Chile https://www.deepskychile.com/fr/
Suport our action : https://www.helloasso.com/associations/ ... mulaires/2
Tom Love
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Joined: Sun Apr 21, 2019 5:57 am

Re: AT2024epj - A mag 10 transient in/near the LMC

Post by Tom Love »

And an updated observation. This is a long (3 hour) exposure which shows a little more detail, though it's a bit noisy as we approach the near infrared. FITS files uploaded to the ARAS database as usual.


at2024epj_ 20240321_838_Tom Love.png
H Alpha in velocity:
at2024epj_ 20240321_838_Tom Love_HAlpha.png
at2024epj_ 20240321_838_Tom Love_HAlpha.png (21 KiB) Viewed 2442 times
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Martinborough, New Zealand. Alpy, Lhires RC12
Olivier GARDE
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by Olivier GARDE »

Nice result Tom !!!
And this is the confirmation of our previous spectrum.

We wil try again next night with our Alpy 600 at 2SPOT in Chile....
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Re: AT2024epj - A mag 10 transient in/near the LMC

Post by Tom Love »

Thanks Olivier. My weather forecast is terrible for the next week, so I think it's over to you for now!
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Martinborough, New Zealand. Alpy, Lhires RC12
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