One of the most dramatic sights through a modest-sized telescope and at low-powers is the appearance of a carbon star
within the field of view, for such stars stand out on their own thanks to their very rich reddish colouration and
appearance and in spite of the hundreds of stars that may surround each such example.
Carbon stars represent cooled supergiants and some white dwarfs which are surrounded by a cloud of dust comprised of various forms of carbon (ex. CH, CN, C3 and SiC2). They are characterized with a surface temperature ranging between 2000 and 3000 degrees Kelvin and are invariably variable in their magnitude (periods in excess of 100 days) and with some exhibiting fluctuations by as much as six magnitudes!
Perhaps the best known carbon star is Betelgeuse (á-Orionis), a cool supergiant which is not only one of the brightest stars gracing our skies (M(v) = 0.58) but is also one of the closest to our solar system (427 + 76 light-years). Of the nearly six thousand stars catalogued by Stephenson, there are over 100 examples whose magnitude is easily within the reach of binoculars and/or very modest amateur telescopes for visual observation.
Please click on the image below to display in higher resolution (1200 x 900)
Proper Star Name:
RA / Dec:
18h 32m 20s /
+36° 59' 56"
B-V Color Index:
Jul 09-10, 2007
22:45 - 00:20 UT+3
AP 160 f/7.5 StarFire EDF