Sky this Week for June 29 to July 5, 2008

The following is a discussion of just a few of the many objects that may be seen up in the summer sky, this week, June 29 to July 5, 2008.

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International Space Station

There is a brief, low pass on Tues July 1 at 4:28 am. The ISS appears in the south; passes through constellation Cetus where it reaches magnitude -0.6, and then disappears in the east-north-east at 4:33 am There is an excellent pass on Wed July 2 beginning at 4:51 am. The ISS appears in the southwest; passes almost directly above in constellation Pegasus where it reaches magnitude -2.4. It disappears in the northeast at 4:57 am. There is a low pass on Thur July 3 at 3:43 am. The ISS appears in the southeast and disappears in the east-northeast (max magnitude -0.6) Another excellent pass on Fri July 4 at 4:06 am. The ISS appears in the southwest, passes through the eastern arm of Cygnus, reaches -2.4 magnitude, passes below Cassiopae, and then disappears in the constellation Auriga in the northeast at 4:09 am. There are a couple passes on Sat July 5. The best one is at 4:28 am when the ISS appears in the west, passes below Hercules and the Little Dipper and then disappears in the northeast at 4:33 am (max magnitude -0.6) There are a couple passes on Sun July 6. The pass at 3:20 am is bright but brief. Look just below the constellation Cassiopae in the northeast. The ISS will pass through Perseus and then disappear just below Auriga in the northeast at 3:22 am (max magnitude -1.6). For more information check http://www.heavens-above.com

Sun

There are no active regions visible on the solar disk as of today, Sunday. On Sunday June 29 sunrise is at 5:37 am and sunset is at 8:43 pm On Saturday July 5 sunrise is at 5:40 am and sunset is at 8:42 pm MDT

Moon

As the week begins, the moon is at lunation 25. The crescent wanes more each day until the moon becomes new on Wednesday July 2nd at 8:19 pm. On Thursday look for the one day old, thin crescent just after 9 pm low in the west-north-west. It sets at 9:28pm. You will probably need to be east I25 or the mountains will cut off your view. You might be able to spot the planet Venus about 6 degrees to the lower right of the Moon. Venus sets at 9:06 pm. On Friday and Saturday the moon will be a pretty view as the earthshine illuminates the lunar night side. On Saturday the moon will be at lunation 3. Crater Endymon can be seen in the northern portion of the crescent. The prominent crater Cleomedes may be viewed just north Mare Crisium. Near the center of Mare Crisium locate crater Picard. Just south of the center of the crescent is the crater Langrenus. A bit farther south are the craters Vendelinus and Petavius. Slew even further south and locate crater Furnerius.

Planets

Mars is low in the west about 11 degrees above the horizon in the constellation Leo. It is nearly in a straight line with the Moon, Regulus, and Saturn on Saturday. Mars is magnitude +1.7 in apparent magnitude and the semi-diameter is 4.4 arc sec. Saturn is in Leo as well. It is magnitude +1.2 in brightness and the semi-diameter is 16.8 arc sec. Jupiter is in constellation Sagittarius. It is magnitude -2.6 in brightness and semi-diameter is 47.3 arc sec. It will be at opposition with the earth next week on July 9th at 2 am MDT. The great red spot crosses the center of the disk at the following times: Sun Jun 29 at 11:24 pm Tues July 1 at 05:11 am Wed July 2 at 1:02 am * Wed July 2 at 8:53 pm (very low) Fri July 4 at 2:40 am * Fri July 4 at 10:31 pm Sun July 6 at 04:18 am * Best position for imaging Mercury rises in constellation Taurus around 4:23 am this week. It is magnitude +0.2 in brightness. Semi-diameter is 7.3 arc sec and the disk is 45% illuminated.

Comets

C/2007 G1 Linear is in constellation Scorpius. Estimated magnitude is +11.9. Location is RA 16 19 14.77 Dec -27 Dec 16 44.6 13.64 at 10 pm on July 5) C/2008 J1 Boattini is in the constellation Cepheus and is reported to be magnitude 11.1 in brightness. Location is RA 22 01 08.30 Dec +65 16 56.1 at 2 am July 5). C/2006 OF2 Broughton is in constellation Taurus. It should be about magnitude 12. (Location is RA 02 25 11.91 Decl +40 15 59.5 at 2 am July 5) C/2007 W1 Boattini reappears in the morning sky this week in constellation Taurus. Its bright ~mag 5.5 and has quite large 20 arc min wide coma. It rises at 3:30 am on July 5. Location is RA 03 30 27.62 Dec +02 29 51.2 on July 5)

Dark Sky Objects

The summer sky offers many tantalizing objects to view especially if you can get far away from the light polluted urban sky. Around 11 pm take a look at the Veil nebula high up in the east in the constellation Cygnus or the Northern Cross. First locate the star called 'Gienah' marking the eastern arm of the cross and then locate the 4.2 magnitude star 52 Cygnus about 3 degrees to the southeast. Slew north so that 52 Cygni is just out of the field of view. The western portion of the Veil or NGC 6960 can then be seen extending across the field. The brighter portion of the Veil, NGC 6992/6996 or the east Veil, is located 2.5 degrees to the east-north-east. From dark skies the eastern portion of the Viel can be viewed in binoculars or scopes of any size. Add a UHC filter to your eyepiece to enhance the contrast. This is a stunning object especially in large aperature telescopes. Delicate, inter-twined nebulous filaments appear to hang in space against a star filled, dark velvet background. Slew slowly and trace the beautiful wispy strands of this wondrous object in the eyepiece view by view. The Veil is a large object covering an area of about three degrees. The fainter northern portion, NGC 6974/6979, is located 1 degree north of 52 Cygni. Look for a triangular shaped haze about 30' and 15' wide called 'Pickering's Triangular Wisp'. Further to the northeast are the 'S-shaped' NGC 6974 and the faint patch of NGC 6979. The Veil nebula is a super nova remnant of a star that exploded many thousands of years ago (age estimates vary widely). It was discovered by William Hershel in 1784. Take a trip down south into constellation Sagittarius as it is now in prime viewing position. Above the spout of the teapot locate Messier 8, the Lagoon Nebula. The lagoon is a oval cloudlike patch that may be seen naked eye in a dark sky location. A bright open cluster called NGC 6530 provides a background sprinkle of stars in the northeastern portion. The luminscent glow of this impressive emission nebula is divided in two by a dark broad lane of dust. It is estimated to be 4100 light years distant. Slew about 1.5 degrees north of the Lagoon and a few arc minutes to the west and you will come across the Trifid Nebula, Messier 20. Put on a UHC or OIII filter and view this relatively bright nebula which is divided unequally by 3 radial dark lanes. It is marvelous to photograph as it is a wonderful color combination of an open cluster, a bluish reflection nebula in the north and a reddish emission nebula in the south.

SummaryM

This week is great time to get out and view the summer sky. The International Space Station may be seen quickly crossing the sky before dawn. Earthshine may be seen on the moon. Through a telescope you can see the rings of Saturn and view Jupiter's red spot. A comet is visible in binoculars before sunrise. Faint distant super nova remnants can be traced and dark dust lanes maybe seen crossing bright emission nebula. Join with the Longmont Astronomical Society or other club in your area as we view some of the great objects visible this week in the summertime sky.