Candidate Unreported Supernova / Hypergiant Outburst
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RA= 228.3101 Dec= 4.2861 , @ 08:00 from the nucleus.
15:13:13.91 +04:17:15.19
No reported SNe on file nearby, which is rather strange since DECaLS is roughly from 2014-2016.
Nothing in SDSS, bright green / yellow in DECaLS DR2 and then it looks like it's fading dim red in DECaLS DR3 😃 ! Can't sort out the proper data for the different filters yet. And also visible as dim red in PanSTARRS image.
DECaLS DR2 looks a bit like it has the same colouring hue and pattern as a cool hypergiant outburst.
SDSS
DECaLS DR2
DECaLS DR3
http://legacysurvey.org/viewer?ra=228.3101&dec=4.2861&zoom=16&layer=decals-dr2
PanSTARRS
image will be replaced but also visible in PanSTARRS as red object equal like DECaLS DR3 image.
Filed in thread https://talk.galaxyzoo.org/?_ga=1.244656832.476670387.1443719759#/boards/BGZ0000007/discussions/DGZ00016qc
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Cool Hypergiant Outburst reference image
https://talk.galaxyzoo.org/?_ga=1.244656832.476670387.1443719759#/subjects/AGZ000cklh
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Looks yellow and green in DECaLS DR2, red in DECaLS DR3.
DECaLS DR2 g and r band dates (1 exposure for both):
- g band 2015-04-17_06:16:11
- r band 2014-08-13_00:23:20
DECaLS DR3 z band dates (3):
- z band 2013-04-01_09:03:17
- z band 2014-08-12_00:52:16
- z band 2015-04-12_06:40:56
So chronology between DR2 and DR3 isn't necessarily as straightforward as it seems.
Most likely scenario now is brightest in 2014-08-12 and still fading in 2015-04-12, which would constrain it on a minimum of 8 months of visability? Hmm except that the DR3 red image can also be from 2014, which gives very little information on the light curve 8) .
Upside it is that the transient is also imaged in PanSTARRS (dates unknown), so there is more information available.
I've also had contact with the lead author of the SN Hunt 248 paper Jon C. Mauerhan. He responded very kind and in his opinion there is a good possibility this is also a cool hypergiant outburst but there is not enough information available to confirm or refute this. And also the host IC 1105 will likely be included in their KAIT automated survey.
Because this one is visible in in DECaLS DR2 + DR3 and PanSTARRS-1 I think there might just be enough exposures to construct a meaningful light curve so I might attempt it in the future.
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Well, that was a YUGE disappointment. Only visible in three DECaLS FITS files out of nearly a hundred FITS files, and only one r band and two z band.... 😕 Yes that is nearly 100 single band images of this galaxy and transient visible in 3 of them. X/
And barely visible in one PANSTARRS-1 y band image.....
I really hoped for many images of the transient, but this is ofcourse not enough by far to attempt to construct a lightcurve.
Ah well, on to other projects I guess.
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by
Budgieye
moderator
Have transients been erased in the images that you looked at? Are the raw images available?
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Ghost_Sheep_SWR
in response to Budgieye's comment.
Hmm I don't think so but not certain, I assumed that if it is visible in some FITS files it should be visible in all FITS files that were taken at the right time. Actually I assumed all FITS files can be seen as 'raw' images.
But I did shortly follow a link were actual RAW images can be obtained, so maybe to be continued...
On a more pessimistic view; the images from DECaLS DR2 and DR3 actually only need 1 green and 2 red detections at minimum ( green + a small red = green with yellow inside).
Thanks for the suggestion!
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I did manage to get RAW files / FITS.FZ files, but then JAVA runs out of memory before it has loaded all the images.
So I get a lot of images all close around target galaxy, almost hilariously perfectly not on target.
Oh and ofcourse DECaLS DR2 is the one Data Release that isn't available anywhere anymore...
Sigh, I'll stop whining and try again in a year or so when this conspiracy thing is over..... 😉
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