AT 2018bkv
RA/DEC (2000)
11:55:50.47 -02:15:00.72
178.9603 -2.2502
Type
---
Redshift
---
Discovery Date
2018-05-09 11:06:00
TNS AT
Y
Public
Y
Host Name
DECaLS
Discovery Mag
21
Filter
g-Sloan
Discoverer/s
Richard Nowell
Spectra
No Data
Light Curves
FilterTel / InstObs-date rangePhotometry
g-SloanSloan_SDSS I-II Spec2016-03-02 06:03:29 - 2018-05-09 11:06:002
Photometry
IDObs-dateMag. / FluxErrLim. Mag./FluxUnitsFilterTel / InstExp-timeObserver/sRemarks
280352018-05-09 11:06:00212ABMagg-SloanSloan_SDSS I-II SpecAs explained earlier, the magnitude values are from a nearby galaxy in SDSS. There is no photometric data for the object I am reporting that is visible in DECaLS. The DECaLS links are: Single image cutouts: http://www.legacysurvey.org/viewer/cutouts/?ra=178.9603&dec=-2.2501&layer=decals-dr5 The two observations in DECaLS that have the possible supernova have the following details: CCD g 535185 N28, 61.0 sec (x,y = 1559,3158) (decam/DECam_CP/CP20160407/c4d_160408_033901_oki_g_v1.fits.fz [58]) (observed 2016-04-08 @ 03:37:13.057250) and CCD g 535537 S21, 55.0 sec (x,y = 498,908) (decam/DECam_CP/CP20160407/c4d_160409_032245_oki_g_v1.fits.fz [8]) (observed 2016-04-09 @ 03:20:57.866482)
280342016-03-02 06:03:2921ABMagg-SloanSloan_SDSS I-II Spec[Last non detection] As there is no photometric data available in DECaLS, I have used photometric data from a nearby SDSS object. The nearby SDSS object is: SDSS J115551.05-021502.5 http://skyserver.sdss.org/dr14/en/tools/explore/Summary.aspx?id=1237650371018358949 I know of no other way to estimate the magnitude on the DECaLS image- sorry. HOWEVER, the last observation date is the DECaLS image date and NOT the SDSS image date.
AT Reportings
IDTime received (UT)SenderReporter/s (Discoverer/s)GroupRADECDiscovery date (UT)Discovery Mag.FilterRelated filesAT TypeInternal nameAssoc. GroupsEnd prop. periodRemarks
183462018-05-13 11:12:29Richard NowellRichard Nowell11:55:50.47-02:15:00.722018-05-09 11:06:0021g-SloanPSN535185 N28This possible supernova was first noticed by myself when using the Galaxy Zoo website. There is no photometric data for the object, so I will have to give as much information as possible via coordinates, cutouts, links and the original Galaxy Zoo discussion. The DECaLS image link is: http://www.legacysurvey.org/viewer?ra=178.9603&dec=-2.2502&zoom=16&layer=decals-dr5 The object in question is the blue one. There is a link to a colour cutout in the 'related links' section below The Galaxy Zoo discussion link is: https://www.zooniverse.org/projects/zookeeper/galaxy-zoo/talk/subjects/20926993 I first noticed the object, but other participated in the discussion- third parties will have to decide who is involved. I am an amateur astronomer and have not reported anything before. All I can do is steer people in the right direction i hope.
Classification Reportings
No Data

Comments

After using the software program APT, more accurate magnitude figures have been calculated. These are based on using SDSS J115551.05-021502.5 r-band and g-band. SDSS J115551.05-021502.5 is nearby and has a spectrum so is a worthwhile reference object.
http://skyserver.sdss.org/dr14/en/tools/explore/Summary.aspx?id=12376503...
The results are:
r-band = magnitude 19.160649832, which is ~19 with an error of less than 5%.
g-band = magnitude 20.8305465783, which is ~21 with an error of less than 5%