In Manx skies... September 2008 ~ compiled by Dave Storey
Moon	New 29^h at 08.12h First Quarter 7^th at 14.04h Full 15^th at 09.13h Last Quarter 22^nd at 05.04h There are no solar or lunar eclipses this month.	Graphic © Copyright CalculatorCat.com Note: All times are Universal Time (UT) BST is currently in force. Add 1 hr. to any quoted times to get local IoM time.
Mercury	Reaches greatest eastern elongation of 27 degrees on the 11^th. Mercury however will be low in the south western horizon and will be poorly placed for observation from the Isle of Man.
Venus	Is an evening star that may be glimpsed in the twilight sky after sunset. It will be unmistakable shining at magnitude -3.9 but again, the planet will be low in the west after sunset and will be poorly seen through a telescope.
Mars	^{Remains poorly placed for observation this month. It will be found low in the west after sunset at magnitude 0.0, fading to +1.6 by the end of the month.}
Jupiter	Will be in the southern sky after sunset in Sagittarius. It will be bright at -2.5 to -2.3. As seen through a telescope, the parallel equatorial belts should easily be seen along with the four bright moons that change positions night after night, either side of the planet.
Saturn	Is on the far side of the sun and will not be visible this month. It reaches solar conjunction on the 4^th.
Uranus	Reaches opposition on the 13^th.It shines dimly in Aquarius at magnitude +5.7 and you will need at least a pair of binoculars to see it. The 95% illuminated moon will occult the planet on the 13^th at 02h23m00s UTC and this will be good time to identify this planet with the moon as a guide. Look at the dark limb of the moon just before the above time and locate the planet just off the lower left dark limb. A telescope will be better to watch the occultation as the moon will be very bright. For the remaining days of the month, use the star charts below to locate the planet. Click on images for a detailed view. Click here for a larger version of the above chart.
Neptune	You will need a telescope and a good star chart to find this planet which shines at a dim +7.8 Use the above chart to roughly locate the planet and the chart left shows a close up view. Graphics based on Guide 8 data.
Meteors	Piscids are active during September and October. There are three maximum dates on 8^th ,21^st September and 13^th October. Rates are very low though
Algol	This star drops from magnitude +2.1 to +3.4 in about 5 hours. Minimum of this star is reached on the following dates as seen from the IoM: 7^th at 02.48h, 9^th at 23.42h and 12^th at 20.30h, 27^th at 04.36h, 30^th at 01.24h. Click here for star chart
Comet	There are no predicted bright comets.
The Stars	Due south at mid month are the constellations Sagitta, Aquila and Scutum. Sagitta is small and its principle stars make up the shape of an arrow. Zeta-Sagittae is a double star that can be seen as a white and blue star of magnitudes 5.7 and 8.8 with a small separation of 8.5” in P.A. 313. You will require a good telescope to see both stars. Between gamma and delta Sagittae is the +8.5 magnitude globular star cluster M71 (NGC6838). It can be seen as a dim fuzzy objects in large binoculars or small telescope. Altair is the bright star south of Sagitta in the constellation Aquila. Altair is relatively close at 17 light years and it has been determined to rotate in a period of 6.5 hours compared to our sun's rotation of nearly one month. This fast rotation gives the shape of Altair as an elliptical object. Flanking either side of Altair are two fairly bright stars of Tarazed (+2.7) and Alshain (+3.7) which makes identification of Altair easy. Tarazed is 700 times more luminous than the sun so if it where placed at the same distance as Altair, it would shine as bright as the planet Venus. To the lower right of Aquila is the constellation of Scutum and this area is bright with dust clouds within our milky way. There are two star clusters in Scutum that look great in telescopes. M11 is most spectacular of the two and resembles the shape of ducks in flight and hence has the nick name of the Wild duck Nebula. The distance to this cluster is about 5,610 light years. M26 is a smaller star cluster south of M11. It has about 40 stars loosely assembles together and is best seen with a good pair of binoculars. Graphic based from Guide 8 There is a variable star to the right of M11 that is well worth watching with a pair of binoculars or small telescope. The above image shows R Scuti's position and the green numbers represent comparison star magnitude. Make an estimate of how bright R Scuti is using these comparison stars once per week and over time, you will end up with a light curve showing the stars change in brightness over time. The star will be seen to vary between +4.5 and fade to +8.8 in a period of 144 days. R Scuti is a RV Tauri type variable and is supergiant star. The star is old and it is believed at some stage in the future, it will shed its outer layers and form a planetary nebula, leaving a white dwarf star behind. Bibliography The Handbook of the British Astronomical Association 2008. BAA. 2007 Stargazing 2008. Heather Cooper & Nigel Henbest. Philip's. 2007 2008 Yearbook of Astronomy. Patrick Moore. MacMillan. 2007 Observer's Handbook Meteors. Neil Bone. Philip's. 1993 Constellations. Josef Klepesta & Antonin Rukl. Hamlyn. 1979 Astronomy with a Small Telescope. James Muirden. George Philip. 1985 Brilliant Stars. Patrick Moore. Cassell. 1996 Atlas of the Night Sky. Storm Dunlop. Collins. 2005 RV Tauri Stars Wikipedia. http://en.wikipedia.org/wiki/RV_Tauri_variable Supergiants. Wikipedia. http://en.wikipedia.org/wiki/Supergiant AAVSO Variable Star of the Month: http://www.aavso.org/vstar/vsots/0700.pdf