Tip:
Highlight text to annotate it
X
Salutations celestial sight seers! I'm David Fuller, welcome to Eyes on the Sky; what's
up this week?
Last week was a couple of globular clusters; how about some open clusters? The stars of
the Summer Triangle are nicely placed at or near the meridian a couple of hours after
dark. Deneb is here, and the "Northern Cross" asterism within Cygnus is here -- Albireo
at the foot, and Gienah and Delta Cygni on the sides, with Sadr in the middle.
In Arabic, Sadr means "chest" - appropriate, given it's location within the swan constellation.
A 2.2 magnitude, spectral F-class supergiant star, it is 150 times the size of the Sun,
and is quite the youngster too - just 12 million years old. Start by finding these two sixth
magnitude stars within the same field of view as Sadr. They are very close by, less than
a degree away. Look at the one slightly further away, then draw a line from it, through Sadr.
Continue that line to a sixth magnitude star, this time almost 2 degrees away -- and, ALL
of these should fit in most finderscope or binoculars fields of view, as they are all
less than 4 degrees apart. Now, between those last two stars is Messier 29. As you can see
in this photo, it has a bit of a smudge-like view to it, and in binoculars, it really isn't
resolved. But with a telescope at moderate magnification you see... you can see... well,
about 6 stars at ninth magnitude. Some call this cluster "The Cooling Tower" ... okay,
I can see that. When I first viewed it myself I saw what appeared to be an open box, like
opening up a present. What do you see there?
Dark Sky Fact: Want better sleep? According to Dr. Joseph Mercola, "Even the tiniest bit
of light in the room can disrupt your internal clock and pineal gland's production of melatonin
and seratonin." Sleep masks can help, but updating our outdated and wasteful lighting
in our homes and on our streets helps us all sleep better.
Now start at Deneb. This hop will take us a total of nine degrees, so more than a typical
seven degrees finderscope field of view. Imagining a line from Sadr, through Deneb, continue
a few degrees until you see a trail of fifth magnitude stars. The first few degrees, we
can see three or four of these fifth magnitude stars, but note how they start to bend slightly
-- this will be towards Andromeda, which is well to the east. Now note how this bent trail
has three fifth magnitude stars, and then a fourth star -- actually a double that is
sixth and seventh magnitude pair. All together, these are two and a half degrees apart. Continue
another four degrees -- on either side you'll see two curved lines of three stars -- I call
these "The Bananas," because I almost went bananas looking for M39 the first time I tried
that.. Then I realized: It's between the bananas! This cluster is tricky though: It's visible
in binoculars or a finderscope as a not-quite-resolvable grouping. But at the eyepiece, unless you
have a VERY wide field of view with a low power eyepiece, you can almost mistake the
stars for not being a cluster. At over half a degree across, they are wider than a full
Moon. I see 18 stars with a 70mm telescopescope, and more with a 6 inch one. It makes an almost
perfect equilateral triangle, and isn't really a "faint fuzzy" so it's great for observers
fighting light pollution. Check it out this week.
Along The Ecliptic: Venus has been west of Spica all summer long, but watch as the goddess
of beauty zips past the star and joins Saturn east of it, with the Moon stopping by the
planets on the 8-th and 9-th. 90 minutes before sunrise, Jupiter rides 40 degrees high in
the sky, followed by Mars at just 20 degrees up, and look for the red planet in Messier
44, the Beehive, on the 8-th and 9-th.
That's all for this week. Keep your eyes on the sky and your outdoor lights aimed down,
so we can all see, what's up. I'm David Fuller, wishing you clear and dark skies.