Ks and r detections of MLS121106:014420+082311
ATel #4605; A Mahabal, M Graham, A Drake, S G Djorgovski, G Hallinan, J. Carpenter, T Yang, M Vallisneri, V Rana, R Williams, C Donalek (Caltech), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), T Nagayama (Nagoya Univ.), S Barway (SAAO), S Hodgkin (IoA, Cambridge), G Vianello (Stanford), D Thompson (NASA), D Kocevski (KIPAC), J Chiang (Stanford), L Petrov (Astrogeo Center), S Larson, E Christensen (LPL)
on 26 Nov 2012; 00:44 UT
Credential Certification: Ashish Mahabal (aam@astro.caltech.edu)
Subjects: Infra-Red, Optical, Transient
We observed the field of the fast CRTS transient MLS121106:014420+082311 (Mahabal et al., ATel 4586) on 2012-11-19 UT starting at 08:30 UT at The Palomar 5m telescope. Using the Wide-field IR Camera (WIRC) with the Ks filter for 3850 seconds, we detect the source. Preliminary reductions put the magnitude at ~19.3+/-0.4 (comparison of ~200 sources matched with UKIDSS).
Further analysis of the GTC data (de Ugarte Postigo et al. ATel 4589) indicates the presence of a faint source at r~26.7+/-0.5 (AB magnitude, 2-sigma detection), using SDSS DR9 stars for the photometric calibration. The r-Ks color is ~7.4 and too red for typical M-dwarfs (Liebert et al., 2000, 2000vlms.conf...99L). The optical flare of >8 mags makes it unlikely to be a cooler brown dwarf.
The transient is the reddest object in the r-Ks image. The detection of the extremely red source points to a likely distant galaxy and a huge intrinsic brightness of the explosion. We have scheduled additional follow-up observations. More, especially at wavelengths longer than r, are encouraged.
Additional details and the preliminary reductions of the Ks image