Background is Nova Cygni 1992 taken October 1996 with the FLWO 1.2m
The
Supernova Group at the Harvard-Smithsonian Center for Astrophysics (CfA)
uses the MMT, the 1.5m Tillinghast telescope and the 48" telescope at
Mt. Hopkins to obtain spectra and images of
recent supernovae .
The SINS collaboration is an international group of astronomers interested
in using the Hubble Space Telescope to study all aspects of supernova
science. Intensive studies of SN1987A,
SN1993J and SN1998S are currently underway. Cool pictures of the
collision of SN1987A with its
circumstellar ring and
evidence for high velocity gas
can be found here.
The
High-Z Supernova Search Team is an international collaboration
of astronomers which discovers and studies
suprnovae at redshifts greater than 0.3. We have found over 30 supernovae at these
redshifts and initial reductions show that
(1) the matter density
in the Universe is low,
(2) that the Universal expansion is accelerating -- requiring a
cosmological constant ,
and
(3) that supernovae plus the comsic microwave background observations suggest that
the geometry of the Universe is
flat .
Pictures of Cataclysmic Variables and Binary Stars:
RXJ 0558.0+5353 is a DQ Her type CV with an orbital period just over
4 hours and a white dwarf spin period of about 9 minutes. MMT spectra
covering nearly an entire orbit were used to construct a Doppler tomograph of the HeII emission. A Doppler tomograph
uses the spectral line shapes and orbital velocity variations to reconstruct
an image of the accretion disk. The distribution of
the emission in RXJ0558 is rather odd and probably results from both the impact of
an accretion stream and heating by X-rays from the spinning white dwarf.
Nova Cygni 1992 (V1974 Cyg) exploded in February 1992. In 1996 a new emission nebula was discovered to the south of the nova.
The nebula is apparently the result of light from the nova exciting interstellar
gas nearby. It is likely that the nebula will expand with time as the light from
the nova propagates further into the surrounding gas.
The light curve of the symbiotic nova
PU Vul from AAVSO data shows an eclipse in 1995
corresponding to spectral variations monitored at
DAO . Another eclipse was
seen during the outburst in 1980 and proves that the orbital period of the
binary is 13.4 years. Details can
be found in the Garnavich (1996) Journal of the AAVSO , vol. 24, No. 2, p. 81.
Pictures of Jets from YSOs:
The region around S187 is filled with dark clouds and
reflection nebulae. In the near-infrared we cut through the extinction and can see
a number of jets in molecular hydrogen (2.12 microns). In images taken with the
Fred Whipple Obs. 1.2m telescope,
one jet appears bent and is
either curved due to an outflow pushing from the north or the jet source is precessing.
The "snake" near LkHa234 in narrow band molecular
hydrogen at 2.12 microns (red), off band at 2.22 microns (blue) and optical R band
0.67 microns (green). Images were obtained with the 3.5m telescope + GRIM-II at the Apache Point Observatory . The "snake" is really
the edge of a dense cloud which is excited by UV radiation from nearby young stars.
The region near HH 110 (2-6) in narrow band molecular hydrogen
emission at 2.12 microns. Two new jets (9-11 and 12-13) are visible
only in the infrared. Details can be found in Garnavich, Noriega-Crespo, Raga and
Bohm (1997), ApJ , 490, 752.
The bright jet Cepheus-E in narrow band molecular hydrogen
emission at 2.12 microns. Images from the 3.5m APO telescope. An IR spectrum of the southern knot taken with the MMT and Rieke
FSPEC spectrometer shows a very rich molecular hydrogen spectrum.
For more information, please contact
Peter M. Garnavich
Other SN links