The bright star Eta Carinae is currently
believed to be probably a binary system of two massive stars, wrapped in a
gaseous envelope formed during the 19th century eruptions and known as the
Homunculus Nebula. The binary would have a 5.53-year period, according to
the cycle first discovered in 1996 by the Brazilian astronomer Augusto
Damineli. As periastron approaches - a situation expected for mid June to
early July, 2003 - the colliding stellar winds of the two components would
generate significant changes in the appearance of several spectral lines.
Some of them will be weakened and eventually disappear with time; others
will be strengthened.
The objective of the spectra shown below was to start a monitoring program
of some spectral lines which are expected to show those changes: the [NIII]
line at 5755 angstroms and the HeI lines at 5876 and 6678 angstroms. We plan
to repeat our observations for the coming weeks until July 2003. The spectra
were taken in Northern Chile (Mamalluca Observatory at the city of Vicuña)
in April 2003 and REA observatory in June 2003 . Our spectroscope was coupled to a 12-in Meade LX-200
scope and a SBIG ST-7E CCD camera.
More
informations about Eta Carinae :
http://www.etacarinae.iag.usp.br/
Sky
&Telescope Magazine , July 2003 - p.32 - 35
REA - Brasil
