[IAUC] CBET 2865: 20111020 : PNV J18441516-1732310

[quai en eps.harvard.edu]

                                                  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 en eps.harvard.edu (alternate cbat en 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