New Moon:
August 12
Full Moon:
August 28
DEEP SKY OBJECTS (DSO's) (Not
the biggest or best, but interesting) :
Minkowski 2-9 (aka: The Butterfly Nebula, or PK 10+18.2): This
planetary nebula was made famous by a beautiful Hubble Space Telescope photograph.
It's faint, at magnitude 13.2, and a larger telescope and high power (~550x)
is needed to resolve the nebula into it's two elongated lobes and it's central
star. It is thought to be very young, created about 1,500 years ago. In August,
look for Minkowski 2-9 early in the night before it gets too close to the western
horizon (It is 42 degrees above the horizon when astronomical twilight ends
at 9:58pm). Also, this nebula is pretty far into the southern sky, located not
far above the top of Scorpius. We could not find it thru an 11" telescope
using a narrow band filter, so we recommend trying at least a 14" scope
with an OIII filter. Good luck! Size: 60"x30" (Location: 17hr 05m
38s RA -10 deg 08.5' Dec, in Ophiuchus).
Humason 1-2 (aka: PK 86-8.1): Planetary nebula. Magnitude 12.7. A medium sized scope (10") should show an hourglass figure at about 400x. Size: 8.3" (Location: 21hr 33m 08s RA +39 deg 38' 04" Dec, in Cygnus. 3 degrees east of Sigma Cygni).
An OIII (Oxygen 3) filter, or even a narrow band filter, will improve the view of the 2 planetary nebulae above. (OIII filters are usually not used on telescopes less than 8" diameter because these filters block so much of the light.)
MONTHLY STAR GAZE (August
10):
Sun: Sets at 8:24pm, astronomical twilight ends at 10:05pm
and begins at 4:58am the next morning. The Sun rises the next morning at 6:49am.
Between astronomical twilights, we get only 6.9 hours of darkness.
Moon: (illuminated 4%) The Moon sets at 7:14pm on the night of the gaze.
Mercury: Not a good time to view.
Venus: Is at inferior conjunction (between us and the Sun) on August 18, so is not visible.
Mars: Rises at 1:17am at magnitude 0.5, it's diameter
is only 7.4 arc seconds. 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 is 33 degrees above
the horizon as it transits the meridian at sunset. It appears quite large, at
41 arc seconds. Jovian-moon events tonight: Io goes into occultation (goes behind
Jupiter) at 10:56pm.
Saturn: Saturn sets at 9:00pm, so it's not a good time to observe.
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.
Neptune: Is at opposition on August 13. Use the same S&T finder charts as mentioned above.
Asteroid Ceres: Ceres rises at 1:02am and culminates at 7:29am, so you'll have to stay up late or get up early to see it. You can find it in binoculars as a faint star-like object at magnitude 8.9 in the constellation Cetus.
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 August star gaze it will transit at 8:30pm and shine at mag 6.9 in the constellation Scorpius. 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. Here is a Sky&Telescope article (below the horizon map click on the link to a black-on-white chart to print). (Location: about 10 arc minutes west of Nu Scorpio)
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 is a mag -3
Iridium flare this evening (Friday August 10) at 9:35pm. Its altitude will be
58 degrees, at an azimuth of 99 degrees (east). These values are as seen from
Mt. Pisgah. Flares will be slightly different from Asheville.
HIGHLIGHTS:
Lammas (a cross-quarter day): August 1st. The ancient
Celts and some East Asian cultures began their seasons on cross-quarter days.
Now they mark the middle of the seasons.
Perseid meteor shower: Peaks at 11:00pm on August 12 (Sunday),
so probably the best time to view the shower will be the morning hours of August
13 (Monday). The morning hours August 12 may be the next-best time to view.
The ZHR (Zenithal Hourly Rate) is about 100, but a single observer should expect
to see no more that about 60 per hour. The moon sets a few minutes before the
sun, leaving the sky dark for the meteors. The best time to watch is from midnight
until twilight, when the meteor shower's radiant is high in the sky and the
moon has set. These meteors are sand and pebble sized debris from comet 109P/Swift-Tuttle.
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)
Note: Links to other web pages are in color. Please go to the web page version of this page to follow those links.
You can check the AstroAsheville Yahoo
group (http://groups.yahoo.com/group/AstroAsheville/) 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:
The indoor club meeting is the first Thursday of every month,
at 6 p.m. at Sim’s
Group located at 230 Short Coxe Ave., Asheville, NC.
Happy Starwatching! Dress Warm!
Blue Ridge Parkway Information
Line is 828-298-0398
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(Much of the above info derived from Sky & Telescope magazine, Ottewell's
Astronomical Calendar, The Night Sky Observer's Guide, Megastar 5.0, Planets202,
the ol' Miller Planesphere, and a little (very little) common sense.)
www.AstroAsheville.org