ATEL Phot no Gaia

Template ATEL reporting photometric follow-up of Gaia alerts without Gaia people.

Title:

Gaia15agj in edge-on galaxy SDSS J095058.70+375758.8 confirmed by Mercator/Maia imaging

Author:

R. I. Anderson (Physics and Astronomy Department, The Johns Hopkins University, Baltimore, MD, USA), L. Palaversa, N. Mowlavi, 
L. Eyer (Department of Astronomy, University of Geneva, Switzerland)

We report confirmation of <a href="http://gaia.ac.uk/selected-gaia-science-alerts"
name="Gaia Science Alerts" title="Gaia Science Alerts">Gaia Science Alerts</a>
transient Gaia15agj, detected by Gaia satelite on 2015 Jun 03 ca. 05 UT.
Images were obtained in U, G, and R bands of the Maia instrument mounted
to the Flemish 1.2m Mercator telescope at Roque de los Muchachos observatory,
La Palma, Canary Islands, Spain, on 2015 June 09 ca. 21UT.

<a href="http://obswww.unige.ch/wordpress/variabilite/files/2015/02/Gaia15agj.png"
name="Gaia15agj">Gaia15agj</a> is located approximately 6.8 arcsec to the
East (= 5.5 kpc for 0.806 kpc/arcsec from NED) of the center of edge-on
galaxy SDSS J095058.70+375758.8 = FGC 0955 = GALEXASC J095059.00+375759.7
which has a redshift of z=0.04 (from NED). SIMBAD identifies this galaxy
as Active Galactic Nucleus 2MFGC 7622.

Gaia15agj was measured at the apparent magnitudes listed in the table below.
These translate to absolute magnitudes of approximately (-18.4, -19.21,
-19.61) in U, G, and R bands, respectively, assuming Aλ
of 0.076, 0.059, and 0.041 in the SDSS u, g, and r filters and distance
modulus (m-M) = 36.11 +/- 0.15 mag (both from NED).

This new source is not present in archival 2MASS/DSS/SDSS images. The location
of the transient off-center in an Sc galaxy renders it a likely supernova
candidate.

MAIA G band 400x400 pixel cut-out image is provided (N is up, E is left and scale is 0.276"/pix).

<table style="width:40%" border="1px solid black" padding="10"> <tr align="center"> </td> <td colspan=2> MJD</td> <td colspan=3> Gaia15agj</td> </tr> <tr align="center"> <td>Gaia detection</td> <td>Observed</td> <td>U</td> <td>G</td> <td>R</td> </tr> <tr align="center"> <td>57,176.2</td> <td>57,182.9</td> <td>~17.7</td> <td>~16.9</td> <td>~16.5</td> </tr> </tr> </table>

The photometric calibrations were obtained using the <a href="http://www.ast.cam.ac.uk/ioa/wikis/gsawgwiki/index.php/Follow-up"
name="CPCS">Cambridge Photometric Calibration Server (CPCS)</a>, designed
and maintained by Sergey Koposov and Lukasz Wyrzykowski.