Crux, also known as the Southern Cross Constellation, is the smallest of the 88 constellations.
Visible primarily in the southern hemisphere and low northern latitudes. The Southern Cross constellation is circumpolar below -34 degrees declination(about 34 degrees South latitude).
With five bright main stars, Alpha, Beta, Gamma, Delta and Epsilon Crucis, this constellation is highly visible.
All five of those stars are magnitude 3.6 or brighter and within 365 light years of Earth.
From the top of the cross which is Gamma Crucis, trace a line south to Alpha Crucis and continue about 4.5 times that distance and you will get near the southern celestial pole.
Sigma Octantis is the southern pole star but is not very bright, so the "Southern Cross" offers a better guidepost.
The pointer stars Alpha and Beta Centauri lead you to it.
The nearby "false cross", an asterism often mistaken for the Southern Cross, does not point to the south pole.
|
The Coalsack Nebula appears just left of Alpha Crucis in the left image. In the outline diagram part of Carina is outlined lower right. |
Right Ascension: 12 hours
Declination: -60 degrees
Visible between latitudes +20 and -90 degrees
Best seen in May at 9:00 PM local time
Named Stars: ACRUX (Alpha 1 Crucis) Mimosa(Beta Crucis) Gacrux (Gamma Crucis)
Alpha Crucis is a triple star. The two close components are divisible in a small telescope and the wide component is divisible in binoculars.
Beta Crucis is a blue giant of magnitude 1.3,
Gamma Crucis, is a double star
Delta Crucis is a blue-white star of magnitude 2.8
Epsilon Crusis is an orange giant star of magnitude 3.6.
Iota Crusis is a binary star system.
Mu Crucis is an optical double divisible in small telescopes and large binoculars.
One of the better features of the constellation is the Coalsack Nebula. A dark patch in the southern Milky Way visible to the naked eye.
Six star clusters reside within the constellation's borders. These are:
NGC4609, NGC4103, NGC4349, NGC4439, NGC4337, NGC4052.
Possibly one of the best views in the night sky and unfortunately only for those in the southern viewing area is the Kappa Crucis Cluster.
Known as the Jewel Box Cluster, NGC4755, is a beautiful open cluster of red, blue, yellow and white super giants
Lying about 7500 light years away and covering about 20 square light years, this cluster contains over 100 stars and has an apparent magnitude of about 4.2.
Visible with the naked eye but simply spectacular in binoculars and telescopes.
A must see for southern hemisphere viewers.
Back To Celestial Solar System Home
|
|
Coalsack Nebula & Jewelbox Cluster pictures courtesy
Copyright © 2007-2013 * ASTROPATAGONIA -. - By Ricardo JUAREZ CONTRERAS