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| Object | Eta Carina/ Keyhole Nebula- NGC 3372 |
| Info |
NGC 3377- Eta Carinae is one of the most massive stars in the visible universe, with probably more than 100 solar masses. At about 4 million times brighter than our local star, makes it one of the most luminous stars known. Eta Carinae radiates 99 % of its luminosity in the infrared part of the spectrum, where it is the brightest object in the sky at 10-20 microns wavelength. Massive stars such as this generally have a short expected lifetime of roughly 1 million years, Eta Carinae must have formed recently in the cosmic timescale; it is actually situated in the heavily star forming nebula NGC 3372, called the Great Carina Nebula, or the Eta Carinae Nebula. It will probably end its life in a supernova explosion within the next few 100,000 years (some astronomers speculate that this will occur even sooner). Because of its high mass, Eta Carinae is highly unstable, and prone to violent outbursts. According to the current theory of stellar structure and evolution, this instability is caused by the fact that its high mass causes an extremely high luminosity. This leads to a high radiation pressure at the star's "surface", which blows significant portions of the star's out layers off into space, in a slow but violent eruption. this image shows the nebula formed by the ejected material. The last of these outbursts occurred between 1835 and 1855 and peaked in 1843, when despite its distance (7,500 to 10,000 light years away) Eta Carinae briefly became the second brightest star in the sky with an apparent magnitude -1. Eta Carina and its nebula is around 7,500 to 10,000 light years away. (Description from SEDS website.) |
| Date | 1st / 12/ 06 |
| Location | BayTop Observatory- Streaky Bay South Australia |
| Instrument | Home built 10" Newtonian (Bob Royce primary) with MPCC coma corrector. System working @ native f4/ 1016 FL 1.35 arcsec/pixel- FOV 23.3x29.4 |
| Mount | Celestron CI700 controlled by a Mel Bartels Goto Control System with Vexta PK264m-01b motors with a pulley and belt system |
| Camera (CCD) | Starlight Xpress HX916 monochrome with Atik manual filter wheel. |
| Exposures | Ha 36'[ 2' sub exposures all unbinned] No dark frames removed. |
| Guiding | none |
| Filters | Astronomik 13nM Ha Filter |
| Notes/ Conditions |
Conditions- have been poor for a week or so. Gusty winds, dry and very dusty conditions. This night/ morning improved seeing wise. Transparency was average to poor. Average FWHM 2.4 with moments going down to 1.7. |