Central Bureau for Astronomical Telegrams
IAUC 7339: 1999gq; 1999go
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Circular No. 7339
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 1999gq IN NGC 4523
K. Ayani, Bisei Astronomical Observatory (BAO); and H. Yamaoka,
Kyushu University, report: "We obtained a wide-band spectrum
(range 400-800 nm; resolution 0.6 nm) of SN 1999gq (cf. IAUC 7337)
with the BAO 1.01-m reflecter on Dec. 26.84 UT. This shows that SN
1999gq is of type-II in the early phase, with a broad P-Cyg H-alpha
profile and H-beta absorption on a blue continuum. Adopting the
NASA/IPAC Extragalactic Database (NED) recession velocity for NGC
4523 (260 km/s), the expansion velocity of the supernova, derived
from the H-alpha absorption minimum, is 7800 km/s. Other broad
absorption features are seen at 580, 559, 510, and 495 nm in the
rest frame of the host galaxy."
S. Jha, P. Garnavich, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
1999gq, obtained by P. Berlind on Dec. 29.54 UT with the F. L.
Whipple Observatory 1.5-m telescope (+ FAST spectrograph), shows it
to be a type-II supernova after maximum light. The spectrum
exhibits strong Balmer features, as well as broad Fe II and Na I
lines. Given the NED recession velocity of 262 km/s for NGC 4523,
the H-alpha P-Cyg profile yields an expansion velocity of 7800 km/s
for the supernova.
M. Armstrong, Rolvenden, Kent, England, reports that he made
an independent discovery of SN 1999gq on a single unfiltered CCD
image taken on Dec. 14.23 UT, at mag 14.2. Poor weather prevented
him from obtaining a confirming image before the LOSS discovery
(cf. IAUC 7337).
SUPERNOVA 1999go IN NGC 1376
M. Salvo, L. Rizzi, A. Pastorello, and M. Turatto, Padova
Astronomical Observatory, write: "Spectra (range 370-910 nm;
resolution 1.1 nm) of SN 1999go (cf. IAUC 7337) have been taken
under poor conditions with the 1.54-m Danish telescope (+ DFOSC) at
the European Southern Observatory, La Silla, on Dec. 28.13 and
29.16 UT. The spectra are very blue and featureless on both dates.
The slope of the continuum on the second date seems redder, and a
hint of a broad absorption centered at 477 nm is visible, probably
due to H-beta. SN 1999go is likely a type-II supernova at a very
early epoch."
K. Krisciunas, University of Washington; and K. Loomis, Apache
Point Observatory (APO), report preliminary infrared J (1.25-micron)
and K' (2.12-micron) photometry for SN 1999go, using the APO 3.5-m
telescope (+ GRIM II camera) with a 7".6-diameter software aperture:
Dec. 27.04 UT, J = 15.25 +/- 0.04, K' = 14.80 +/- 0.06.
(C) Copyright 1999 CBAT
1999 December 30 (7339) Daniel W. E. Green
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