Central Bureau for Astronomical Telegrams
IAUC 4516: 1987N; N IN M31
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Circular No. 4516
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444
SUPERNOVA 1987N IN NGC 7606
H. E. Schwarz, M. H. M. Heemskerk and L. Mantegazza, European
Southern Observatory, correct their earlier report (IAUC 4514) and
note that SN 1987N seems to be a somewhat overluminous type I
object. Strong Si II 598 and 637 nm appears at blueshift 13 300 and
12 500 km/s, O I 789-800 nm at 11 700 km/s and weaker Ca II 850-
854 nm at 9300 km/s. All lines are in absorption, and the velocities
refer to the absorption minimum. On Dec. 20.04 UT V = 13.4.
P. G. Murdin, Royal Greenwich Observatory, communicates:
"Astronomers at Teide Observatory (Tenerife) and Roque de los
Muchachos Observatory (La Palma) report from observations during
Dec. 17-19 that SN 1987N is a luminous unreddened type I object,
close to maximum on Dec. 18. Spectra (range 500-1000 nm) with the
4.2-m William Herschel Telescope by R. E. Ellis (Durham), A.
Pickles (Groningen) and M. Rowan-Robinson (Queen Mary College) show
the characteristic 615-nm Si II feature and Mg, S, O and He absorptions
typical of type I, broadened to about 12 000 km/s expansion
velocity. Spectra (320-680 nm) with the 2.5-m Isaac Newton Telescope
by P. Murdin show additional blue absorption lines, including
Ca II and interstellar absorption from our Galaxy (including
Ca II H at 0.02 nm equivalent width and Na D), but none was detected
from NGC 7606. Photometry with the 1.5-m Carlos Sanchez Telescope
by J. Cepa, A. Mampaso, F. M. Insertis and F. Sanchez (Instituto
de Astrofisica de Canarias) gives the following infrared magnitudes:
J = 13.2, H = 12.1, K = 11.9. CCD images on Dec. 18 with
the 1.0-m Jacobus Kapteyn Telescope by P. Charles (RGO) E. Harlaftis
(Oxford) and G. Machin (Oxford) show the supernova above a
spiral arm of NGC 7606, with preliminary photometry of V = 12.8,
U-B = -0.2, B-V = +0.6, V-R = +0.3. This is consistent with type
I at maximum with E(B-V) about 0."
M. M. Phillips and S. R. Heathcote, Cerro Tololo Interamerican
Observatory, report that spectra obtained by M. Hamuy on Dec.
21 and 22 confirm the supernova as of type Ia. CCD photometry by
S. Kirhakos with the 0.91-m telescope gives V about 13.4, B-V about +0.1.
NOVA IN M31
J. Bryan, Georgetown, TX, reports his discovery of another
nova in M31 at R.A. = 0h39m48s, Decl. = +40 58'.9 (equinox 1950.0). The
object was of mpg = 16.8 on Dec. 20.13 UT.
1987 December 22 (4516) Brian G. Marsden
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