Electronic Telegram No. 4078 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network NOVA SCORPII 2015 = PNV J17032620-3504140 S. Nakano, Sumoto, Japan, reports the discovery by Tadashi Kojima (Tsumagoi, Agatsuma-gun, Gunma-ken, Japan) of an apparent nova (mag 8.2) on four frames (limiting magnitude 12.0) taken on Feb. 11.837 UT using a Canon EOS 60S digital camera (+ 150-mm f/2.8 lens) mounted on a Sky-Memo equatorial mount. Kojima measured the postion of the new object to be R.A. = 17h03m26s.2, Decl. = -35d04'14" (equinox 2000.0; Nakano measured position end figures 26s.11, 17".6 and red magnitude 8.1 +/- 0.4 from the same frame, estimating an uncertainty of +/- 5" for the position. Nakano posted Kojima's image at website URL http://www.oaa.gr.jp/~oaacs/image/PnovaSco.jpg. H. Maehara, Okayama Astrophysical Observatory, writes that nothing is visible at the reported position on archival CCD images taken with the Kamogata-Kiso- Kyoto Wide-field Survey (KWS) set-up (105mm-f.l. f/2.0 lenses + SBIG ST-8XME cameras + Bessell V and I_c filters) between 2013 Mar. 21 and 2014 July 27 (typical limiting magnitudes V = 12.5 and I_c = 11.5). The variable was designated PNV J17032620-3504140 when it was posted at the Central Bureau's TOCP webpage. Additional CCD magnitudes for PNV J17032620-3504140: Feb. 10.827 UT, [11.0 (Kojima); 12.826, 9.5 (T. Noguchi, Katori, Chiba-ken, Japan, 0.23-m f/6.3 Schmidt-Cassegrain reflector; position end figures 26s.15, 17".5; image posted at URL http://park8.wakwak.com/~ngc/images/PNVinSco_20150212.jpg; communicated by Nakano); 12.841, 9.5 (K. Yoshimoto, Yamaguchi, Japan; Nikon D5100 digital camera + 180-mm f/2.8 lens; position end figures 26s.13, 18".0; image posted at http://orange.zero.jp/k-yoshimoto/PNV-J17032620-3504140.jpg; communicated by Nakano); 13.7, R = 8.6 (E. Guido and N. Howes; remotely using an ITelescope 0.50-m f/6.8 astrograph at Siding Spring; position end figures 26s.19, 18".1; UCAC3 catalogue reference stars; animation showing a comparison between their image and a red Digitized Sky Survey plate from 1991 is posted at website URL http://bit.ly/1MjCWV3; their annotated image is posted at URL http://bit.ly/1vrf9rz); 13.827, 9.4 (Noguchi; 10-s exposure; limiting mag 15.0; position end figures 26s.17, 17".9; UCAC4 reference stars; image posted at URL http://park8.wakwak.com/~ngc/images/PNVinSco_20150213.jpg; communicated by Nakano); 13.865, V = 9.73 +/- 0.04 (Maehara; KWS cameras); 13.865, I_c = 8.26 +/- 0.08 (Maehara; KWS cameras); 14.746, B = 10.6, V = 9.7, R = 9.3 (T. Yusa, Osaki, Japan; remotely using an iTelescope 0.32-m reflector at Siding Spring; position end figures 26s.17, 17".8; BVR color image posted at URL http://space.geocities.jp/yusastar77/supernova/PNinSco_150215.htm); 14.88, B = 10.75, V = 9.76, R_c = 8.69, I_c = 8.15 (K. Yoshimoto, Yamaguchi, Japan; 0.16-m f/6.3 reflector + ST9XEi camera + Johnson-Cousins filters; four 15-s exposures; communicated by Nakano); 18.202, 9.5 (G. Masi; remotely using a 43-cm telescope at Ceccano, Italy; altitude 10 degrees; position end figures 26s.16, 18".1); 19.744, V = 10.34 +/- 0.01 (R. Kubala, Berlin, Germany; via E. O. Waagen, AAVSO); 22.786, V = 11.11 +/- 0.04 (K. Hills, Hartford, Cheshire, UK; via Waagen); 26.403, V = 11.53 +/- 0.01 (J. Hambsch, Mol, Belgium; via Waagen); Mar. 1.711, V = 11.74 +/- 0.60 (Hills); 4.663, V = 12.31 +/- 0.13 (Hills); 8.705, V = 12.75 +/- 0.04 (Hills); 11.409, V = 13.35 +/- 0.04 (Hambsch); 14.639, V = 13.30 +/- 0.10 (Hills); 16.409, V = 13.58 +/- 0.04 (Hambsch). Guido adds that the star NOMAD-1 0549-0492872 (magnitude V = 17.0) is located 0".37 from PNV J17032620-3504140, and that 2-MASS 17032617-3504178 is 0".33 away. P. Schmeer, Bischmisheim, Germany, notes that that star GSC2.2 S2223100108184 has position end figures 26s.149, 17".58; NOMAD1 0549-0492872 has position end figures 26s.168, 17".85 (YB6 catalogue); and 2MASS 17032617-3504178 has position end figures 26s.176, 17".82 (with magnitudes J = 13.4, H = 12.5, K = 12.2). Visual magnitude estimates for PNV J17032620-3504140, reported in part by E. O. Waagen, AAVSO: Feb. 12.313 UT, 9.5 (A. Amorim, Florianopolis, Brazil); 14.829, 10.2 (A. Pearce, Nedlands, W. Australia); 16.308, 10.1 (L. Camargo da Silva, Sao Jose, Brazil); 16.807, 10.4 (Pearce); 18.497, 10.3 (B. Cudnik, Houston, TX, U.S.A.); 20.459, 11.0 (L. Shotter, Uniontown, PA, U.S.A.); 22.830, 11.2 (Pearce); 27.822, 11.7 (Pearce); Mar. 2.769, 12.1 (Pearce); 4.818, 12.7 (Pearce); 11.819, 13.3 (Pearce); 18.400, 13.1 (Shotter). F. M. Walter, Stony Brook University, reports on continuing SMARTS observations of N Sco 2015 = PNV 17032620-3504140: Approximately nightly BVRIJHK photometry with the SMARTS 1.3-m reflector (+ Andicam) at Cerro Tololo through March 8 shows a rapidly fading S-class light curve, with a brief hiatus in the decline, at Day 10 (Day zero taken to be Feb. 11.837 UT, the time of discovery), some 1.5 mag beneath the peak magnitude observed (V = 9.50 on Day 1.01); this hiatus is most evident in B and V, where the nova brightened by about 0.2 mag. The nova is fading in all bands at a rate of about 0.14 mag/day. There is as yet no evidence of an underlying red giant, with magnitudes J = 10.2, H = 9.9, and K = 9.3 on Day 25 (Mar. 9.9 UT). Nineteen spectrograms were obtained with the SMARTS Chiron echelle spectrograph on the Cerro Tololo 1.5-m reflector (R = 28000; range 460-880 nm) between Days 1.0 and 25.0. The object is best described as an "He-N"- type nova, but with some strong Fe II multiplet 42 lines (blended with He I) early on. There are similarities to N Sco 2014 (CBET 3841) and V745 Sco (IAUCs 4820, 4821, 4822, 4825). The initial spectrum (Day 1.0) shows a tripartite H-alpha emission line, with outlying peaks at +4500 and -4800 km/s. The peaks faded rapidly. The red peak blended with He I 668-nm by Day 4; the blue peak was lost about Day 10, under a narrow Fe II line. The central H-alpha emission component, unconfused due to the low level of the broader emission, decreases in width from about 3.5 nm on Day 3 to 0.8 nm by Day 20. The N III/C III Bowen blend at 463-465 nm is prominent, with particularly narrow emission lines (FWHM around 100 km/s). A plethora of narrow Fe II lines are blueshifted about 170 km/s with respect to heliocentric; these may arise in a red giant companion. He II 469-nm appeared in emission between Days 4.0 and 5.0, rapidly strengthened, and became double-peaked by Day 10.0. Unusual for fast "He-N"-type novae, prominent P-Cyg profiles (suggestive of mass loss) are visible at velocities of -4100, -3200, and -2300 km/s on Day 1 in H-alpha, H-beta, He I 588-nm, and O I 777-nm. The features at -4100 and -2300 km/s strengthened on Day 2.0, but are absent by Day 4.0. An narrow absorption feature at -500 km/s appeared in the H-beta and He I lines on Day 13.0 and persisted through Day 16.0. SMARTS observations of novae are made possible by a grant from the office of the Provost of Stony Brook University; SMARTS schedulers at Yale are thanked for accommodating this program. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2015 CBAT 2015 March 20 (CBET 4078) Daniel W. E. Green