Epsilon Lyrae
Epsilon Lyrae (abbreviated ε Lyr ) is the fourth brightest star in the small constellation Lyra , close to the bright Vega (α Lyrae). It is a quadruple star and about 160 light years away from us. The approximate celestial coordinates are: RA 18h 45m, δ + 39 ° 35 '.
The star is a double star with an angular distance of 3'27 "which is visible to very sharp eyes . This makes it a much more difficult eye tester than Alkor in the Big Dipper. Its two components (magnitude 4.7 and 4.6 mag ) are themselves narrow telescopic double stars about 3 "spacing.
The view in a six- to eight-inch model at around 150x magnification is particularly attractive . The two components ε¹ and ε² can still be seen in the field of view at the same time and are clearly separable (2.7 "and 2.3"). In addition, the position angles differ by almost 90 ° - i.e. H. one of the close double stars is roughly north-south, the other east-west. All four stars appear white, which is a rare combination. The orbital times are about 1170 and 585 years.
- literature
- Rudolf Brandt : The telescope of the star friend , double star tables I and IV in the appendix. Kosmos-Verlag, Stuttgart 1958
- Joachim Herrmann : DTV Atlas Astronomy , p. 225th DTV-Verlag, 14th edition, Munich 2000
- M.Feiler, P.Noack: Deep Sky Reiseatlas , Kartenblatt 14 (Cyg / Lyr). Second edition, Oculum-Verlag , Erlangen 2005.