Linear Polarization Measurements of Nova Sco 2015 (PNV J17032620-3504140)
ATel #7161; S. Muneer, G. C. Anupama, A. V. Raveendran (Indian Institute of Astrophysics, Bengaluru, India)
on 1 Mar 2015; 17:20 UT
Credential Certification: G.C. Anupama (gca@iiap.res.in)
We report here the first polarimetric observations of Nova Sco 2015 (PNV J17032620-3504140). The nova was observed during 19-25 Febuary 2015 with a two-beam, broadband, multi-channel polarimeter attached to the 1-m Carl-Zeiss telescope at the Vainu Bappu Observatory, Kavalur, India. The BV passbands approximate that of Johnson's UBV system and the RI passbands approximate that of Kron-Cousins system. The measured linear polarization, not corrected for ISM polarization is provided below.
February 19; JD 2457073.5
R: P(%)=0.93(0.09); PA (deg): 118(3)
February 20; JD 2457074.49
V: P(%)=1.59(0.22), PA(deg)=100(4); R: P(%)=1.08(0.09), PA(deg)=116(3); I: P(%)=0.70(0.28), PA(deg)=95(11)
February 21; JD 2457075.49
V: P(%)=1.56(0.22), PA(deg)=107(4); R: P(%)=1.02(0.08), PA(deg)=109(2); I: P(%)=1.21(0.12), PA(deg)=123(3)
February 22; JD 2457076.48
V: P(%)=1.66(0.20), PA(deg)=119(3); R: P(%)=1.39(0.08), PA(deg)=115(2); I: P(%)=0.95(0.18), PA(deg)=119(5)
February 23; JD 2457077.48
V: P(%)=2.25(0.18), PA(deg)=108(2); R: P(%)=1.40(0.07), PA(deg)=115(1); I: P(%)=1.43(0.11), PA(deg)=108(2)
February 24; JD 2457078.46
V: P(%)=1.52(0.17), PA(deg)=119(3); R: P(%)=1.38(0.04), PA(deg)=112(1); I: P(%)=1.20(0.10); PA(deg)=107(2)
February 25; JD 2457079.47
B: P(%)=2.83(0.31), PA(deg)=96(3); V: P(%)=1.52(0.20), PA(deg)=106(4); R: P(%)=1.25(0.06), PA(deg)=114(2); I: P(%)=1.57(0.09), PA(deg)=108(2)
The numbers inside the brackets indicate the probable errors in the corresponding quantities.
We could obtain only one set of observation in the B band. There is an indication that the linear polarization increases towards blue. This trend is different from that shown by the interstellar polarization which normally peaks in the V-R spectral region. There is also a suggestion that the polarization increased a little in the RI bands during the period of our observations. Therefore, a major fraction of the polarization can be attributed to the Nova.
The magnitudes of nova in VRI bands observed on the night of 25 February are about 0.3 fainter than those observed on the previous night.
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