Observing Calendar for August / September – By Steve Woodbridge

Sky Diary — By pcburns on August 18, 2009 at 1:00 pm

Observing Calendar

August 13th to September 12th 2009 (all times BST)

FAS is pleased to present the highlights of the August sky prepared by Steve Woodbridge. If it is clear on the 11th and 12th of August, one will have a chance of seeing the meteors in the Perseid Meteor Shower – the year’s most dependable meteor shower. It is not, perhaps,the best year to observe the Perseids as a waning gibbous Moon will be rising in the north-east and its glare will obscure the fainter meteors. There are also several opportunities to see the ISS (click here for details).

Date
August 14th	Jupiter at opposition in Capricorn (near d – altitude 23º at culmination). Worth checking out what is happening in the bands and belts this year – there are rumours of significant changes.
August 15th	Moon rises after midnight meaning darker evening skies for the next two weeks
August 15th	Io occults Europa (0125)
August 16th	Deneb culminates at midnight. Deneb is the nineteenth brightest star in our night sky, but one of the truly bright stars being a type A supergiant and around 1500 light years away. Near Deneb lies a magnificent nebulous complex known as the North American nebula. Can you see it visually and with what equipment? It has even been seen with the naked eye from a dark site and using a nebular filter. Images welcome.
August 16th	Io eclipses Ganymede – twice (0050 and 2131)
August 17th	Neptune at opposition in Capricorn – just west of Mu. It is a tiny 2.9” in diameter – can anyone get an image, or spot Triton it’s largest moon which is about 16” from the planet. Neptune’s magnitude is 7.9 so it can be found in binoculars using a good star map.
August 17th	Io occults (2158) and eclipses (2211) Europa
August 23rd	Io eclipses Ganymede (0418)
August 24th	Mercury reaches Greatest Elongation East. However as it is only 4º up at sunset in the UK it will not be practical to observe (although well-placed from the Southern Hemisphere).
August 25th	Io occults (0023) and eclipses (0108) Europa
August 26th	New Moon
August 29th	Moon sets after midnight.
August 29th	Mars close to Messier 35 in Gemini. Mars is a morning object at present – 5.7” in size, magnitude 1.0 and 38º up at dawn on this date.
August 16th	Venus at maximum elevation (28º) at sunrise (0553). Can you follow it into the daytime sky with the naked eye?
September 1st	Io occults (0303 and 2052) and eclipses (0455 and 2200) Europa
September 2nd	Enif (? Pegasi) culminates at midnight. Enif is normally a second magnitude orange supergiant star, although once had a giant flare in 1972 which made it briefly a first magnitude star. Near Enif is Messier 15, one of the brightest globulars in the sky at magnitude 6.2. Its size is 7’ visually, slightly larger photographically. Anyone willing to offer an image?
September 4th	Full Moon
September 4th	Saturn’s rings in line with the Sun (equinox on Saturn). Unfortunately Saturn is only 11º from the sun and so this will be almost impossible to observe – unless you are a camera on the Cassini spacecraft!
September 8^th-9th	Io occults (2321) and eclipses (0039) Europa
September 12th	Algol, Beta Persei at minimum just after 1am by the Cracow elements. Algol is the first ever discovered eclipsing binary ranging from magnitude 2.1 to 3.4. Algol’s period does change over time as there is mass transfer in the system. Different sources are giving differing predicted times of minima, so it would be worth checking out when you think the minimum is. The eclipse lasts 10 hours and the best comparisons are g Andromedae (2.1), e Persei (2.9), a Trianguli (3.4), and k Persei (3.8). Other good observable minima over the period are on August 20^th around 2.30am and on August 22^nd around 11.30pm.