Home Printer-Friendly Page Download a Sky Map for this month
New Moon:
Sept 11
Full Moon:
Sept 26
DEEP SKY OBJECTS (DSO's) (Not
the biggest or best, but interesting) :
Two Edge-on Galaxies:
NGC 891 (Caldwell 23): Mag 9.9, size is 9'x2' thru an 8"
scope and 12'x2.5' thru an 18" scope. It appears large, so it seems dimmer
than it's magnitude would indicate. A 12" scope is needed to see it's dark
lane. 16" scopes show much detail, such as the "chimneys" in
the dark lane. This galaxy in inclined 88.2 degrees to our line of site (1.8
degrees from edge-on). It bears a strong resemblance to NGC4565 (mag 10.4 and
14'x1.5' in size) in Coma Berenices, which is not visible this time of year.
NGC891 is about 30 million light years away, which is about 12 times further
than the Andromeda Galaxy. (Location: 02hr 23m RA +42 deg
21' Dec, in Andromeda)
NGC676: Mag 9.6, size is about 3'x1' thru amateur scopes. A superimposed
star from our galaxy makes this galaxy's core appear deceptively bright. Faint
individual stars just east of center can be seen thru 16" scopes. It's
location is relatively easy to find in a finder scope, after you find the bottom
of the deep "V" in Pisces. This galaxy is about 80 million light years
away. (Location: 01hr 49m RA +05 deg 54' Dec, in Pisces)
(Note:These 2 galaxies transit at about 2:00am in Mid-September. This
puts them highest in the sky just after many lights are turned out for the night.)
MONTHLY STAR GAZE (September
7):
Sun: Sets at 7:48pm, astronomical twilight ends
at 9:18pm and begins at 5:39am the next morning. The Sun rises the next morning
at 7:07am. Between astronomical twilights, we get 8.3 hours of darkness.
Moon: (illuminated
12%) The Moon sets at 5:53pm on the night of the gaze and rises at 4:05am the
next morning.
Mercury: 9 degrees above the western horizon at sunset, so not a good time to view.
Venus: Was at inferior conjunction (between us and the Sun) on August 18. On the morning of the gaze it is already 24 degrees above the eastern horizon at sunrise, it's 13%-illuminated crescent is a whopping 48" in diameter, and is a very bright magnitude -4.4. It will reach it's brightest, mag -4.8, by the end of the month but it will have shrunk to a 33%-illuminated, 34 degree diameter crescent!
Mars:
Rises at 12:28am at magnitude 0.2; it's diameter is only 8.4", too small
to see surface features. It's apparent size will increase during the summer, reaching
almost 16 arc seconds in late December. In 2005, Mars was the closest it will
be for the next 13 years.
Jupiter & it's moons:
Jupiter, at magnitude -2.1, is 28 degrees above the horizon an hour after sunset,
so catch it as early in the evening as possible. Next month will be too late.
It has decreased in size from 41" to 38" during the last month. There
are no Jovian-moon events tonight.
Saturn: Saturn sets at 7:15pm, a half hour before sunset.
Uranus: Is at opposition on September 10, so it's a good time to find it. See a finder chart on page 60 of the July issue of S&T. At 3.7" in diameter, it appears about half the size of Mars. High magnification will show a slightly blue, round "ball" shape.
Neptune: Was at opposition on August 13. Use the same S&T finder charts as mentioned above. Even though Neptune is just past opposition, it appears only 2.3" in diameter. Even with high magnification it may appear only as a "fuzzy" star.
Asteroid Vesta: Earlier this summer Vesta, at magnitude 5.4, was the brightest it had been in 18 years. Next year Vesta will get only as bright as mag 6.4. On the night of the September star gaze Vesta is the brightest asteroid, easily visible in 7x50 binoculars. It will transit at 7:12pm and shine at mag 7.3 in the constellation Ophiuchus. Vesta is not the biggest asteroid, but it is the brightest. This is because it reflects much more of it's light than do most other asteroids. (Location: tonight, about 2 degrees east of Jupiter. See page 58 of the September S&T magazine for a map showing Vesta's location thru then end of September.)
Asteroid (Dwarf Planet) Ceres: On the night of the September star gaze, Ceres is the second-brightest asteroid. It rises at 11:30pm and culminates at 5:59am, so you'll have to stay up late or get up early to see it. You can find it as a star-like object at magnitude 8.5 near the western hoof of Taurus. Ceres is the largest "asteroid" and has enough mass to have formed into a spherical shape. For this reason it is the only "asteroid" that is now called a "dwarf planet".
Satellites: You can check for satellite passes by going to
"www.heavens-above.com"
and logging-on as registered user "Astro Asheville" with password "12345".
There are several observing site to choose from. Choosing the correct site is
important only for seeing the Iridium flares.
There
are no fly overs by the HST or ISS, and are no Iridium flares on the night of
the gaze.
HIGHLIGHTS:
Sept
18: Harvest Moon. This is the full moon nearest the fall equinox.
The Moon is on the celestial equator at this time, and is progressing "up
" (westward on) that equator. This helps compensate for the Moon's eastward
movement against the stars, so the Moon rises only about 30 minutes later each
night, instead of it's usual 50 minutes. This is more pronounced the further north
you are, until eventually, at 62 degrees north, the Moon is actually rising earlier
each night.
Sept 22: The Fall equinox. The Sun crosses into the southern
celestial hemisphere. Night and day are equal length.
TERMS:
AFOV=apparent field of view / dec=declination
/ EP=eye piece / FOV=field of view / ISS=International Space Station / HST=Hubble
Space Telescope / ly=light year / mag=magnitude / ra=right ascension /
culminates=transits the meridian=when an object as at its highest point in the
sky / transit=passing in front of another object / ZHR=zenithal hourly rate (basically,
the most meteors 1 person could see in 1 hour under ideal conditions)
CLUB STARGAZE:
You can check the AstroAsheville
Yahoo group [or call Tim @ 251-0040 or John @ 251-1933 (before 5:00) or 667-9268
(after 5:00)] for a go/no-go decision and to verify location.
CLUB MEETING:
Indoor club meetings are usually the first Thursday of every
month, at 6 p.m. in the Sims
Group offices (230 Short Coxe Ave., Asheville, NC.)
Happy Starwatching! Dress Warm! Blue Ridge Parkway Information
Line is 828-298-0398
.............................................................................................................................................................................
(Much of the above info is derived from Sky & Telescope magazine, Ottewell's
Astronomical Calendar, The Night Sky Observer's Guide, Burnam's Celestial Handbook,
Megastar 5.0, Planets202, Cartes du Ciel, the ol' Miller Planesphere, and a little
(very little) common sense.)