OGLE-IV Pre-discovery Observations of Nova PNV J17355050-2934240
ATel #8811; P. Mroz, A. Udalski (Warsaw University Observatory), on behalf of the OGLE team
on 13 Mar 2016; 21:33 UT
Credential Certification: Przemek Mroz (firstname.lastname@example.org)
Subjects: Optical, Cataclysmic Variable, Nova, Transient
The discovery of a nova candidate PNV J17355050-2934240 was reported in the CBAT TOCP site. The near-infrared spectroscopy confirmed the object is a classical nova (ATel #8809).
The star is located in the field BLG654 regularly monitored by the OGLE-IV Survey
. The last pre-outburst image was taken on 2016 March 6.36759 UT, when there was not any object at the nova position. The next image of this field was acquired on 2016 March 8.31853 UT (three days before the discovery) and the nova already had I = 12.15 mag. The star was saturated on the subsequent images (taken on March 9.32467, 10.32022, 11.31545, and 13.31603 UT). The typical saturation limit is ~12-12.5 mag.
The equatorial coordinates of the nova are: R.A. = 17:35:50.41, Decl. = -29:34:23.8 (J2000.0). The progenitor of this nova is undetected in the OGLE deep template image of the field BLG654, meaning it was fainter than I > 22 mag.
The nova is heavily reddened. According to the VVV extinction map (Gonzalez et al., 2012, A&A 543, 13), the color excess E(J-Ks) in 2 arcmin region around the nova is 0.82 +/- 0.13 mag. Based on the location of the red clump in the color-magnitude diagram, we estimate E(V-I) ~= 2.45 +/- 0.10 mag, which corresponds to A_V ~= 5.4 mag (Nataf et al., 2013, ApJ 769, 88).
Precise I-band photometry of the nova will be available via the OGLE CVOM system
once the star fades below the saturation limit.
Finding charts can be found here.