During the summer
much time can be spent looking at the summer triangle of bright stars, Vega in
the constellation of Lyra, Altair in Aquila and Deneb in Cygnus.
I would like
to draw your attention to rho Aquila a 4.9 magnitude star in the constellation
of Aquila the Eagle which is just visible to the naked eye on a clear dark
night, although binoculars will show it easily.
It’s an
unremarkable star, but it has a remarkable claim. In 1992 it moved from Aquila to
the neighbouring constellation of Delphinus the Dolphin.
Rho Aquila
is about 160 light years away and it is moving very slowly across the sky at a
rate of 0.06 of an arc second per year. Since the star was catalogued as rho in
1603 by Bayer it has moved about 24 arc seconds across the sky and now is in
Delphinus.
Of course
the constellation boundaries are quite arbitrary, it’s not really
significant. However if you want a good pub
quiz question, in which constellation will you find the star Rho Aquila?
The next
naked eye star due to get a free transfer to another constellation is Gamma
Caelum in the constellation of the Sculptor’s Tool which has a magnitude of 4.6
and will transfer to the constellation of Columba the Dove in around the year
2400!
No comments:
Post a Comment