Astronomy Club of Asheville, NC

May - 2007

""I know that I am mortal and a creature of the day; but when I search out the massed wheeling circles of the stars, my feet no longer touch the earth, but, side by side with Zeus himself, I take my fill of ambrosia, the food of the gods." Ptolemy

MOON:
Full Moon: May 2
New Moon: May 16

CLUB INDOOR MEETING: Thursday, May 3.

STAR GAZE (May 18):
Sun: Sets at 8:29pm
Moon: (illuminated 7%) The Moon sets at 11:11pm.

Venus: Venus is high and bright (mag -4.2) in the west after sunset. As you look at Venus, realize that when you see it in the evening sky it is heading toward us and will next pass between the Earth and the Sun. (When you see Venus in the morning sky, it is heading away from us and will next pass on the far side of the Sun.)

Jupiter & it's moons: Jupiter rises at 9:57pm and culminates at 2:52am, when it is 32 degrees above the horizon.
          Tonight a Jovian moon and it's shadow transit the face of Jupiter:
          1. Io's shadow begins transit at 11:34pm, when Jupiter will be only 16 degrees above the horizon.
          2. Io begins transit at 12:00am, when Jupiter is 20 degrees above the horizon..
          3. Io's shadow ends transit at 1:45am, when Jupiter is 30 degrees above the horizon.
          4. Io ends transit at 2:11am, when Jupiter is 32 degrees above the horizon (That's only 37 minutes before Jupiter's culmination. Jupiter doesn't get very high this time of year.)
          By the end of Io's transit, the Great Red Spot has almost reached Jupiter's meridian.

Saturn & it's rings: Saturn will be 54 degrees above the horizon at sunset and it sets at 2:06am Saturday morning. Saturn culminates at 7:12pm. This planet reached opposition in February, so the shadow of the planet on it's rings is not prominent, but can it still be seen, giving a noticeable"3-D" effect.
          The "star" located about 1.5 ring-diameters away to the SSW is really the moon Titan. Other fainter moons are visible closer to the planet's west side.

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 0 Iridium flare tonight at 10:43pm, and a brilliant mag -8 (yes, negative 8) flare the following night at 10:37pm!! Both are in the ENE direction, about 70 degrees high. These mag values are as seen from Mt. Pisgah.

DEEP SKY OBJECTS (DSO's)  (Not the biggest or brightest, but interesting):
1. Star Lalande 21185 (aka: Hip 54035 or HD 95735): Lalande 21185 is a class M2 red dwarf star (about one-third the mass of our sun and about 3,000 degrees K), 8.3 light years away at magnitude 7.5. It is the 4th closest star system to the sun (the 6th closest star).  The other closer star systems also are or contain red dwarfs:  Alpha Proxima Centauri, Barnard’s Star in Ophiucus, and Wolf 359 in Leo.  Of these three red dwarfs, only Barnard’s star is detectable in most amateur telescopes.

Lalande 21185 is one of the brightest red dwarfs in our solar neighborhood.  Astronomers think that Lalande 21185 may have a binary stellar companion and/or several Jupiter size planets.  It also has a large proper motion of about 5” of arc per year.  Barnard’s star has a larger proper motion of over 10” of arc per year.

Lalande 21185 obtains its name from Joseph Lalande, a Frenchman and friend of Charles Messier.  He was also director of the Paris Observatory in the 1700s.  He cataloged close to 50,000 stars during his lifetime.

For detail location information use: Sky Atlas 2000.0, Chart 6 and Uranometria 2000, vol. 1, chart 55, left side. (Location: In Ursa Major near the Leo Minor border, 11hr 4m RA    +36deg 2' Dec)

See this red dwarf and a red giant in the same 47' FOV:  Located 47 arc minutes WNW of Lalande 21185 is a 6th magnitude M2 class red-giant star designated Hip 53726.  The 2 stars fit nicely in the same low-power field-of-view (FOV).  Hip 53726 appears 4 times brighter than Lalande 21185, yet it is over 100 times farther away at 894 light years!!

2. NGC4565: A highly elongated, edge-on spiral galaxy in Coma Berenices. Very nice, especially for a non-Messier object! The dust lane is visible in 8" scopes under dark skies. Mottling and knots are visible in larger scopes. 31 Million light years away, and about 125,000 light years in diameter. Catch it early in the evening when it is high, or in March when it is high after midnight and many offending community lights are turned off. Magnitude 9.6 (Location: 12hr 36m RA    25deg 59' Dec)

3. OMEGA CENTAURI: The most impressive Globular Cluster visible from Earth, too bad it is so far south. But to see it at all from this far north, May after dark is a good time to check it out if you have a clear view to the southern horizon. It crosses the meridian in mid-May at 10:00pm. Being 15,500 light years away, it is one of the nearest globulars, but is still over half as far away as the galactic center (although 68 degrees to the west of galactic center, and a little south). There are about 1,000,000 stars in this 300 light-year-diameter cluster. Magnitude 3.5 (Location: 13h 27m R.A. -47 deg 29' Dec)

4. Delta Corvi (Double stars): a fairly bright, white primary paired with a dim pale blue secondary, 24.2" separation; Magnitudes 3.0 & 9.2. Their distance from Earth is 88 light years & true separation is 650 a.u. (16x that of our sun and Pluto). This pair is the upper-left star in Corvus. (Location: 12h 29.9m R.A.    -16 deg 31' Dec)

5. STF 1669 CORVI (Double stars): a pair of equally bright yellow stars at 5.4" separation; Magnitudes 6.0 & 6.1. Their distance from Earth is 278 light years, & true separation is 426 a.u. (7x that of our sun and Pluto). (Location: 12hr 41m R.A.   -13 deg 01' Dec).

6. 28 CORVI (Double stars) : a closer pair, yellow and white, at 2.2" separation; Magnitudes 6.5 & 8.6. Their distance from Earth is 81 light years, & true separation is 53 a.u.. This makes their separation only 1.4x that of our sun and Pluto (40 a.u.)! It is easy to imagine the size of the Solar System placed here. Just sit there at the eye piece and imagine the sun in place of the primary star, and Pluto 80% of the way to the other star. Then sit there and contemplate a while longer. (Location:12hr 30m R.A.    -13 deg 24' Dec) See the orbital plot at Richard Dibon-Smith web site:http://www.dibonsmith.com/crv_b28.gif.

7. Ghost of Jupiter Nebula (aka NGC3242, or Caldwell 59) :
                                                                      (Location: In Hydra, 10hr 24m R.A.   -18 deg 39' Dec)

HIGHLIGHTS:
May Day, or Beltane: May 1, one of the 4 "cross quarter" days in the standard calendar, it marks the beginning of Solar Summer in the old agrarian calendars. This is the quarter of the year with most sunlight (May,June,July), as opposed to the quarter that is hottest (June,July,August). See this Weather ALmanac article: http://www.islandnet.com/~see/weather/almanac/arc2000/alm00may.htm. (Begin celebrating at sundown on April 30, as did the ancient Celts. Their days began and ended with sunset.)

Eta Aquarid meteors on night of May 5 & morning of May 6. These are particles from comet Halley. Regretfully, the waning gibbous moon will overpower these meteors.

TERMS
AFOV=apparent field of view / AU=Astronomical Unit, the average distance from the Sun to the Earth / 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).
Times are Eastern Standard/Daylight Time unless othrwise noted.

CLUB STARGAZE:
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