Date + Time
............................... 25 / 9 /2012 -
17:45 UTC Location .................................... "Nunki
Observatory" - Skiathos Optics .........................................
Celestron
C11 HD f/10 Tools
..........................................
Maxim dl Camera ..................................... SBIG
ST-2000XM with CFW10 (Astrodon filters) Exposure Time.......................
Luminance: 120 X 0.5sec RGB: 80 X 1sec (each) More Details ...........................
Environment Temperature : 21oC Camera Temperature 0οC Mount ....................................... Paramount
ME Guiding ....................................
Unguided Processing Details ................ Photoshop ,
Maxim , Notes ........................................ Weather:
8/10 - Transparence: 2/6 - Humidity : 78%
Target details ......................... Vega
(α Lyr, α Lyrae, Alpha Lyrae) is the brightest star in the
constellation
Lyra, the
fifth brightest star in the night sky and the second
brightest star in the northern
celestial hemisphere, after
Arcturus. It is a relatively close star at only 25
light-years from Earth, and, together with Arcturus and
Sirius, one of the most luminous stars in the
Sun's
neighborhood.Vega has been extensively studied by
astronomers, leading it to be termed "arguably the next most
important star in the sky after the Sun."Vega was the
northern
pole star around 12,000 BC and will be so again around
AD 13,727.
Vega is only about a tenth of the age of the Sun, but since
it is 2.1 times as massive its expected lifetime is also one
tenth of that of the Sun; both stars are at present
approaching the midpoint of their life expectancies. Vega
has an unusually low abundance of the elements with a higher
atomic number than that of
helium.Vega is also a suspected
variable star that may vary slightly in magnitude in a
periodic manner. It is
rotating rapidly with a velocity of 274 km/s at the
equator. This is causing the equator to bulge outward
because of
centrifugal effects, and, as a result, there is a
variation of temperature across the star's
photosphere that reaches a maximum at the poles. From
Earth, Vega is being observed from the direction of one of
these poles.
Based on an observed excess emission of
infrared radiation, Vega appears to have a circumstellar
disk of dust. This dust is likely to be the result of
collisions between objects in an orbiting
debris disk, which is analogous to the
Kuiper belt in the
Solar System. Stars that display an infrared excess
because of dust emission are termed Vega-like stars.Irregularities in Vega's disk also suggest the presence of
at least one planet, likely to be about the size of
Jupiter,in orbit around Vega. |