Electronic Telegram No. 2865 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 PNV J18441516-1732310 S. Nakano, Sumoto, Japan, reports the discovery by Yukio Sakurai (Mito, Ibaraki-ken) of a possible nova (mag 11.2) in Sagittarius (at R.A. = 18h44m15s, Decl. = -17d32'.5, equinox 2000.0) on two 15-s CCD frames (limiting mag 13.0) taken on Oct. 3.425 UT using a Fuji FinePix S2 Pro Digital Camera (+ Nikon 180-mm f/2.8 lens); nothing is visible on a frame taken by Sakurai on Sept. 27.5 (limiting mag 12.4). Sakurai obtained a confirming jpeg image (limiting mag 12.4) on Oct. 4.45, from which Nakano measured mag 11.5 and position R.A. = 18h44m15s.20, Decl. = -17d32'36".7 (uncertainty +/- 2"); Nakano measured mag 11.3 and position end figures 15s.16, 31".0 (uncertainty +/- 4") from the discovery image. The object was designated PNV J18441516-1732310 when it was posted on the Central Bureau's TOCP webpage. Nakano reports mag 10.0 and position end figures 14s.94, 34".2 (UCAC3 reference stars) for PNV J18441516-1732310 from an unfiltered CCD image (limiting mag 17.5) taken by T. Noguchi (Katori, Chiba-ken, Japan; 0.23-m f/6.3 Schmidt-Cassegrain reflector + BITRAN BT-11E camera) on Oct. 7.415; Noguchi adds that a star is present very close to this position on a red 1992 Digitized Sky Survey image. Additional magnitudes for PNV J18441516-1732310 from R. A. Koff (Bennett, CO, U.S.A.; Meade 0.25-m f/10 Schmidt-Cassegrain reflector + Apogee AP-47p camera; image scale 2"/pixel), who also measures position end figures 14s.94 +/- 0s.01, 33".8 +/- 0".1 (UCAC3 reference stars): Oct. 6.084, 10.8 (unfiltered); 11.079, 10.6 (unfiltered), V = 10.8 +/- 0.1, I = 8.4 +/- 0.1. Koff adds that stars with nearly identical positions in the USNO B-1.0 and UCAC3 catalogues have magnitudes therein that are 3-5 magnitudes dimmer than the star's current brightness. Koff has posted an image of PNV J18441516-1732310 at website URL http://antelopehillsobservatory.org/SNpictures/PNVJ18441516-1732310final.jpg. Seiichiro Kiyota (Tsukuba, Japan) reports magnitudes B = 13.00, V = 11.64, R = 10.14, and I = 7.62 for PNV J18441516-1732310, obtained on Oct. 5.15 UT with a 25-cm reflector (+ SBIG ST-10 CCD camera) at Mayhill, NM, U.S.A. (Global-rent-a-scope 004), using comparison star TYC 6284-570; he measures osition end figures 14s.95, 33".5, and his image is posted at website URL http://meineko.sakura.ne.jp/ccd/PNV_J18441516-1732310-111005.jpg. Joseph Brimacombe, Cairns, Australia, provides unfiltered mag 11.4 and position end figures 14s.94, 33".9 for PNV J18441516-1732310 on Oct. 5.171. A. Amorim, Florianopolis, Brazil, reports visual mag 11.5 on Oct. 9.937 for the variable. Wolfgang Renz, Karlsruhe, Germany, reports that a search of the major astrometric catalogues spanning observations from 1972-2002 indicate that PNV J18441516-1732310 is perhaps a Mira-type variable star that is relatively red, suggesting its identity with the infrared objects IRAS 18413-1735 and AKARI 1844149-173233, with an amplitude of 3-4 mag in the visual band and a period close to one year; he provides the following mean position from a dozen catalogues: R.A. = 18h44m14.959, Decl. = -17d32'33".58 (equinox 2000.0). Renz also suggests possible identity with NSV 11264. M. Fujii, Fujii Kurosaki Observatory; and M. Yamanaka, H. Akitaya, T. Ui, and T. Okushima, Hiroshima University, report that they obtained low- resolution optical spectra of PNV J18441516-1732310 on Oct. 6.5 UT at the Fujii Kurosaki Observatory (R = 500) and Higashi-Hiroshima Observatory of Hiroshima University (R = 400). The spectra show the absorption-lines sequence of the TiO band between 500 and 950 nm. The line profile is similar to that of an M-type star. This indicates that PNV J18441516-1732310 should be classified as a Mira-type variable star. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 October 20 (CBET 2865) Daniel W. E. Green