Scorpius
Observing >
There are 88 constellations in the heavens surrounding this planet of ours. Essentially none of them actually looks like what it is supposed to represent. Aquarius looks nothing like a guy toting water. Pegasus better resembles my 4th grade teacher (hollering at me!) than a horse. And Camelopardalis looks nothing like a… well, like a camelopardalis!
But there is one constellation in the southern summer skies that actually
looks like what it is named for. That would be Scorpius, the Scorpion.
And it is a cosmic shopping mall, filled with all kinds of objects most
of which can be seen naked-eye or with just a pair of binoculars.
Scorpius is that big bunch of stars in the south in the shape of a giant,
melting, letter "J." One of the standouts in this collection
of stars is the bright reddish star toward the "top" of Scorpius.
It is the Heart of the Scorpion, Antares.
Antares gets its name from the Greek, Anti-Ares, which loosely translated
means "this guy looks like Mars." It is an indescribably immense
red giant star, more than 7000 times wider than our sun and giving off
nearly three million times more energy! The Big Red Guy gives off more
energy in one second than what the sun can manage in an entire month!
Of the 13 bright stars that make up Scorpius, nine are found at about
500-600 light years away. This grouping is no coincidence! They were probably
formed at the same time from the same star nursery.
There are several other famous stargroups like this - called associations
- out there. Orion, that great winter constellation, and the Big Dipper
in Ursa Major are two other neighborhoods of sibling stars which grew
up together and are now spread out far and wide.
Binoculars can show you a different class of grouped stars. Find Antares
in your binoculars. In the same field of view, with Antares in the center,
look just to the right of the great star. That little fuzz ball you see
is called M4. A medium-sized scope can bring out even more beautiful detail.
M4 is a "globular cluster," a collection of tens to hundreds
of thousands of stars, some of the oldest stars in the universe. There
are many "globs" in the night skies. They were formed even before
the Milky Way galaxy took shape, more than 10 billion years ago.
Another sort of collection, called
an open cluster, can be seen near the Stinger of the Scorpion. Look there
at the pair of stars, Shaula and Lesath. (Seeing them is all one needs
to explain why they are also called The Cat's Eyes.)
Find these two in your binoculars, then move one field of view to the
"left." You should find a beautiful concentration of stars which
appear as a collection of diamonds.
This is M7, an "open cluster." These stars are a relatively
young brood, about 260 million years old. Notice that although they are
grouped, they are loosely so, and are nowhere near as dense with stars
as the globs.
A neighboring open cluster, just to the north of M7, is M6. This family
is only about 100 million years old - mere infant-toddlers.
The "open" clusters, as opposed to the "globs," were
formed relatively recently and within the Milky Way itself, part of the
ongoing star-making machinery spiral galaxies like our own are famous
for.
Enjoy your trip to the Scorpion! Maps are at http://firstlightastro.com/icolumn.html.
Until next time, clear skies!
Posted by Administrator at 2000.08.21 09:17 AM | Comments (0)
