AT2024bch - a possible bright supernova in NGC3206

[Robin Leadbeater]

Patrick Wiggins reports a possible supernova AT2024bch in NGC3206
https://www.wis-tns.org/object/2024bch
It is currently reported mag 15.5 but at this distance it could potentially reach mag 12 (if a type Ia with no extinction)
It is well place for northern hemisphere observers

Cheers
Robin

[E Soubrouillard]

Hello,
Here is a spectrum taken last night. Despite the very low signal noise ratio, we can see a wide line in emission around 4680 A and a short Ha line slighty redshifted. More exposure is required asap. Possible sn type II.
Poor weather conditions : fog and few high level clouds
Cheers
Emmanuel

[Robin Leadbeater]

Hi Emmanuael,

Yes this is a type II. Claudio Balcon was able to classify it using an earlier spectrum during the break out phase when the Balmer and He lines were clearer. You can see the same effect in my animation of SN 2023ixf here
https://britastro.org/observations/obse ... 5370c08912
Claudio's classification as a IIn might be wrong as the early narrow lines have now almost disappeared in your spectrum. It could be a normal type II/IIP
If it is, it should develop strong broad Balmer P Cygni lines like here
https://britastro.org/observations/obse ... 4d96087a30

Cheers
Robin

[E Soubrouillard]

If it is, it should develop strong broad Balmer P Cygni lines like here
https://britastro.org/observations/obse ... 4d96087a30

Excellent reason to continue observations.

[E Soubrouillard]

Hello,

Here is a spectrum taken last night with the new Alpy 200 spectrograph.
47 days after first detection, sn2024bch develops strong broad Balmer lines due to the very high ejection velocities (mesured at about 8000 km/s)
P cygni profil not yet visible.

Cheers
Emmanuel

[Robin Leadbeater]

Nice Spectrum! A close match to SN2023ixf at a similar age
https://britastro.org/specdb/data_graph ... s_id=13980

Cheers
Robin