Discovery of the Galactic nova VVV-NOV-020
ATel #10247; R. K. Saito (Universidade Federal de Santa Catarina), D. Minniti (Universidad Andres Bello, The Milky Way Millennium Nucleus, Center for Astrophysics and Associated Technologies, Vatican Observatory), J. E. Drew (University of Hertfordshire), R. Greimel (University of Graz), P. W. Lucas (University of Hertfordshire)
on 6 Apr 2017; 12:23 UT
Credential Certification: Roberto Saito (saito@astro.ufsc.br)
Subjects: Infra-Red, Optical, Nova
We report the discovery of another likely Galactic nova from the VVV survey observations in the Milky Way disk (Minniti, D., et al. 2010, NewA, 15, 433). VVV-NOV-020 is located at equatorial coordinates RA/DEC(J2000)=13:32:45.82,-62:29:59.5, corresponding to l,b=307.6821,-0.0098 deg.
VVV-NOV-020 lies in the overlap region of the disk VVV tiles d085 and d047, giving twice as many observations for a total of 96 epochs. The object was beyond detection in the images taken before March 8 2013, indicating that the progenitor was fainter than Ks<18.4 mag - the limit of the VVV photometry for stellar sources in the field. On March 8, a Ks=10.17 mag source was observed, declining in brightness steadily thereafter, reaching Ks~16 mag at the end of the 2015 observing season.
The estimated extinction in the field is A_V=19.2 mag, A_K=2.1 mag (Schlafly, E., et al., 2011, ApJ, 737, 103), in agreement with the VVV reddening maps. There are cataloged r, i and H-alpha observations from the VPHAS+ survey on 2nd April and July 15 2013 (Drew, J.E., et al., 2014, MNRAS, 440, 2036). The object faded by about 2 mags in VPHAS+ data between these two dates. This decline from the eruption parallels our Ks-band data. The bright H-alpha magnitudes indicate strong line emission in the narrowband.
The tables below report the VPHAS+ and VVV photometry for VVV-NOV-020. VVV observations from June 2011 to May 2012 shows no detection at the target position and are not listed. VVV photometric flags are described in Saito, R.K., et al. 2012 (A&A, 537, A107).
VPHAS+ observations:
HJD mag merr flag band
56385.17 15.04 0.01 -1 H-alpha
56385.18 17.65 0.01 -1 r
56385.19 16.86 0.01 -1 i
56459.04 no detection u
56459.06 no detection g
56489.01 17.34 0.02 -1 H-alpha
56489.02 19.69 0.04 -1 r
56489.03 18.57 0.03 -1 i
VVV Ks-band observations:
HJD mag merr flag
56360.13379997 10.17 0.01 -9
56362.14114806 10.27 0.01 -9
56365.13996833 10.10 0.01 -9
56366.28164508 10.25 0.01 -9
56371.23695002 10.27 0.01 -1
56372.13305956 9.90 0.01 -9
56373.14976611 10.42 0.01 -9
56374.14101732 10.22 0.01 -9
56374.21367113 10.34 0.01 -9
56375.13802566 10.50 0.01 -9
56375.26642348 10.35 0.01 -9
56376.10415891 10.55 0.01 -9
56376.25578250 10.60 0.01 -9
56377.11204459 10.50 0.01 -9
56407.20858775 11.23 0.01 -1
56408.03530850 11.25 0.01 -9
56408.04123607 11.28 0.01 -9
56431.99170618 11.57 0.01 -9
56438.23434904 11.62 0.01 -1
56439.16260803 11.66 0.01 -1
56439.18726351 11.72 0.01 -1
56445.17442805 11.71 0.01 -1
56447.17514335 11.41 0.01 -9
56447.18238486 11.47 0.01 -1
56448.14756874 11.79 0.01 -1
56448.19760144 11.78 0.01 -1
56449.16453118 11.65 0.01 -1
56449.17033813 11.64 0.01 0
56449.20437460 11.61 0.01 -1
56450.15815139 11.71 0.01 -1
56450.16441119 11.73 0.01 -1
56458.98716522 11.97 0.01 -1
56459.16875219 12.06 0.01 -1
56460.97500743 11.97 0.01 -1
56463.10755842 11.94 0.01 -1
56463.12772274 11.96 0.01 -1
56464.07719016 11.97 0.01 -1
56464.14476373 11.58 0.01 -1
56464.96906102 12.06 0.01 -1
56464.98723570 12.03 0.01 -1
56465.07103270 11.95 0.01 -1
56465.09008033 11.95 0.01 -1
56465.12069497 12.08 0.01 -1
56798.97985839 15.05 0.06 -1
56798.99263364 14.87 0.04 -1
56799.01103680 14.75 0.03 -1
56804.05836740 15.04 0.05 -1
56804.07154737 14.94 0.03 -1
56809.07596333 15.36 0.05 -1
56809.98780973 15.32 0.05 -1
56810.00626586 15.38 0.04 -1
56810.03119058 15.12 0.04 -1
56810.08233090 14.89 0.03 -1
56811.01630230 14.77 0.03 -1
56811.08144622 14.90 0.04 -1
56812.98463436 15.56 0.07 -1
56812.99062410 15.57 0.05 -1
56813.00681056 15.39 0.04 -1
56813.01946585 15.18 0.03 -1
57113.13488916 15.43 0.05 -1
57115.10430353 15.82 0.07 -1
57138.06960566 15.59 0.09 -1
57146.25544505 16.32 0.06 -1
57150.00308175 15.40 0.06 -1
57152.98825047 15.39 0.06 -1
57165.01739690 15.68 0.06 -1
57165.10099050 16.48 0.14 -1
57178.19718415 15.84 0.11 -1
57178.20711878 15.71 0.11 -1
