Nova Candidate

https://www.legacysurvey.org//viewer/?ra=177.3246&dec=12.1128&layer=ls-dr10-early-grz&zoom=15

Screen Shot 2022-10-06 at 4.35.00 PM
DR10 image

Screen Shot 2022-10-06 at 4.35.10 PM
DR9 image

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After looking at the single exposures for DR9 and DR10, I can confirm this is a nova.

Cool! Thanks Keiran

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Nice find! I agree with Keiran_Collins, I can confirm as a #supernova. If you want it to be reported in the TNS (Transient Name Server), it can be.

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That would be awesome- how do I report it?

Reporting archival transients (not technically supernovae)

  • Get an account at the Transient Name Server
  • Make very sure you have a real transient (not an artifact, asteroid etc. etc.) that isn’t already reported (check TNS among others)
  • get the right coordinates for the transient
  • get a magnitude, either given by the survey (prefered) or calculate / measure yourself
  • get the right info regarding telescope / time / date / position
  • get an (archival) image / date / time where the transient is absent

Hmm I think this about covers most of it for reporting (archival) transients, any way the older the less chance it is known with all the robotics going on nowadays…

GL!

Agreed, it does look like a transient that was in the same spot for a while.

A bit odd is that it seems to be brightest (of all observations) on 2017-03-05 in r band, but has already faded a great deal one day later (g band)

Can’t check JPL now, but looks irrelevant

With great help from others I pioneered the ‘report your archival transient at TNS’ over at Galaxy Zoo, but only transients with given mag. Others took it a step further and started measuring their own mags with APT, I never got that far…

Thank you AFJ!

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You’re welcome;

For good help you should be over at Galaxy Zoo, the TNS reporting of archival transients is still going strong there (not me anymore though, I’m 99% Voorwerp hunter)

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IMHO it is better to calculate an apparent magnitude. You can do this with APT photometry program and a certain mathematical equation. The given magnitudes in the DECaLS catalogs are often not reliable. And often there are no given magnitudes in the DECaLS catalogs

If you calculated an apparent magnitude, you can also calculate the absolute magnitude using the ‘quantities derived from redshift’ list found in NED Search and the calculated apparent magnitude. In this case you need the list from the host galaxy and you need the ‘luminosity distance’ to calculate. There are several ways to calculate an absolute magnitude but I use this one. The only disadvantage is that no k-correction is applied. You can add this to the report as extra information, although it is not mandatory.

Also important, always check whether the object is visible in PanSTARRS or not regarding the first appearance. Sometimes PanSTARRS has an image with an earlier date than DECaLS.

If the JPL links don’t work on the ‘single exposures’ site, always do a manual search for asteroids at the time and date of the first appearance with the JPL Small Body identification tool. You should not assume too easily that it is not an asteroid!

And don’t forget to check the TNS, Simbad Search, NED Search but also the RBS (Rochester Bright Supernova) pages to see if the candidate already has been reported. Often the candidate is not reported in the TNS but is reported in one of the other databases.

And last but very important. One image (single exposure) showing the transient is not enough data to report. And also multiple images with the same date with only a few minutes apart is not enough data to report. You must have at least two images (single exposures) with different dates where the transient is visible. And preferably even more.

Ine :stars::dizzy:

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