Central Bureau for Astronomical Telegrams
IAUC 7556: Poss. N IN Pup
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Circular No. 7556
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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POSSIBLE NOVA IN PUPPIS
I. Platais, V. Kozhurina-Platais, and M. I. Zacharias,
Universities Space Research Association; and N. Zacharias, U.S.
Naval Observatory (USNO), report the following position for this
variable star (cf. IAUC 7554) from preliminary reduction of two CCD
frames (scale 0".905/pixel) obtained on Jan. 4.227 UT with the USNO
0.20-m f/10 astrograph at Cerro Tololo Interamerican Observatory:
R.A. = 7h37m56s.882, Decl. = -25o56'58".88 (equinox 2000.0; 100
Tycho-2 reference stars; estimated standard error 0".05 in each
coordinate). The star's red magnitude was measured to be 8.7.
There is a star (red mag 13.6; epoch 1999 Mar. 3) in the first USNO
CCD Astrographic Catalog (UCAC1) at position end figures 56s.883,
58".88; the same star is also visible (visual mag 13.1) on a pair
of the Yale/San Juan Southern Proper Motion program plates taken on
1967 Jan. 18. Preliminary reductions indicate that its absolute
proper motion is small: mu(R.A.) cos Decl. = -0".0047/yr and
mu(Decl.) = +0".0064/yr (standard error 0".004/yr).
R. M. Wagner, LBT Observatory; C. B. Foltz, MMT Observatory;
and S. G. Starrfield, Arizona State University write: "A spectrum
(range 420-750 nm, resolution 0.35 nm) of the possible nova,
obtained on Jan. 4.23 with the 6.5-m MMT (+ blue-channel
spectrograph), is dominated by emission lines arising from Fe II
(multiplets 27, 37, 38, 42, 46, 48, 49, 55, 73, and 74); Na I 589.4
(1) and 616 (5) nm; and Ca I 658 (1) nm. The emission lines
exhibit P-Cyg profiles, and overlapping emission and absorption
makes positive spectral identifications difficult. Emission lines
arising from H I and He I do not appear to be present. Measurement
of several absorption troughs gives a maximum expansion velocity of
about 900 km/s. The spectrum is not typical of 'Fe II' classical
novae, recurrent novae, or symbiotic novae such as PU Vul or RR Tel."
Spectroscopic reports have also been received from several
observers using smaller instruments: M. Fujii, Okayama, Japan
(0.28-m reflector, 2000 Dec. 31.7 UT); W. Liller, Vina del Mar,
Chile (0.20-m Schmidt telescope + objective prism, 2001 Jan.
3.235); and O. Shemmer, E. Leibowitz and J. Dan, Wise Observatory
(Jan. 4.00). They all report the prominent emission lines of Fe
II; though they also report He I at 587.6 nm, Wagner notes this
could also be due to Na I 589.4-nm. Fujii's spectrum (resolution
about 1 nm) suggests that H-beta is weak or absent; emission in the
other spectra close to H-alpha is likely due to Ca I 658.0-nm,
according to Wagner. Shemmer adds that the continuum rises by a
factor of 1.5 from 750 to 400 nm, and the spectrum shows emission
line widths of Fe II, O I, Na I, and Ca II that correspond to an
expansion velocity of about 1000 km/s.
(C) Copyright 2001 CBAT
2001 January 6 (7556) Daniel W. E. Green
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