Terry's Sky Notes
PEGASUS - This month the Great Square of Pegasus will be prominent in the southern night sky.
Markab - a Pegasi - A blue-white star nearly 5x the Earth’s radius and 133 light years away.
(RA 23h 05m Dec +15ᵒ 12' Spec.type A0 IV).
Scheat -b Pegasi - An orange-red semi-regular variable star having 2x mass of the Earth and
196 light years away. (RA 23h 04m Dec +24ᵒ 05' Spec.type M2.5III-IIIe).
Algenib – γ Pegasi - A sub giant blue-white star 9x mass of Earth and 390 light years away.
(RA 00h 13m Dec +15ᵒ 11' Spec.type B2 IV).
Alpheratz - a Andromedae – A binary system (RA 00h 08m Dec +29ᵒ 05'). The Primary star is a
blue-white (Spec.type: B8IVpMaHg) with a mass 4x that of the Earth’s mass and having a periodic orbit of 97 days. The Secondary star, a white (Spec.type: A3V), mass 2x that of the Sun.
NGC 7078 (Messier 15) – A globular cluster of about 100,000 stars which, under good seeing conditions, may be seen with the unaided eye as a fuzzy blob.
The cluster is 175 light-years in diameter and about 33,000 light-years away.
The relatively densely packed centre core of the cluster is believed to have undergone some form of collapse surrounding what may be a black hole.
(RA 21h 30m Dec +12ᵒ 10')
NGC 7331 Caldwell 30 – An unbarred spiral galaxy, which is similar in size, shape and mass to the Milky Way. But at 40 million light-years away you’ll surely need a large telescope to view this object. The central bulge of stars is thought to be contra-rotating to the rest of the galaxy.
(RA 22h 37m Dec +34ᵒ 25')