The five planets that can be seen with the naked eye return to October nights. Find Jupiter reaching its highest point in the southern sky shortly after dusk in October. Shining brightly at a magnitude of -2.6, Jupiter will be the brightest object in the southern sky other than the moon throughout the month. On Oct. 26, find the moon just to the right of Jupiter. Read more
This is the best time of year to see the star Fomalhaut, near the southern horizon in Piscis Austrinus. It is a near neighbour, only 25 light-years away, and the centre of a newly forming planetary system in the shape of dusty debris. The appearance in the east this month of the brilliant Pleiades star cluster in Taurus heralds the approach of winter. The Pleiades are surely one of three great spectacles of the northern sky the others being the Summer Triangle (now moving towards the western horizon), and, to be visible next month, the glorious Belt and Sword of Orion. Read more
Ed ~ Just to remind newcomers, there is daily coverage on this sites Calendar section (accessed from the main control menu).
Jupiter will reach its highest point in the southern sky soon after darkness falls during October. Normally this would be the best time to view the great planet with a telescope, but in this case the images may be blurred by turbulence. Earth's atmosphere cools rapidly after sunset as it loses its daytime heat, and this tends to produce unsteady viewing. Use low magnification for better images. Read more
In Greek mythology, the winged horse Pegasus flew over the Mediterranean. Today, the myth takes form every October, when his starry namesake prances above a sea of watery fall constellations. High in the south after sunset, Pegasus dominates the celestial landscape thanks to the Great Square, its most salient feature. The Great Square makes a handy guide to Pisces, the Fishes, especially the dim little fish just to the east. Immediately below the Great Square, the Circlet of Pisces represents the larger fish.
The transition from the summer to winter constellations occurs during October. The summer triangle, which connects the bright stars Vega, Deneb and Altair, is overhead after sunset and gradually sets at midnight. A very beautiful object for small telescope observers is the "Ring Nebulae" lying very close to Vega. Read more
For October, the Moon will be full moon on the 4th, this is the "Harvest Moon", closest to the Autumnal Equinox in late September. The first two weeks find the moon waning in the morning sky. Halloween finds the moon just past first quarter on the 26th, so the waxing gibbous moon and Jupiter in the south make for sharing telescopic views with the trick-or-treaters in the evening twilight. Read more
The Constellation of Ophiuchus Next to Hercules and standing on Scorpius, you will find the large constellation of Ophiuchus. The brightest star of Ophiuchus is Rasalhague, which means Head of the Snake Charmer and is only a magnitude 2. You can see this constellation, which looks a bit like a misshapen triangle under less than ideal conditions. Ophiuchus, the Serpent Bearer, was formerly known as Serpentarius. In mythology, it is associated with the healer Aesculapius, who became so skilled that he was able to bring the dead back to life. To avoid depopulation of the underworld, Jupiter disposed of Aesculapius with a thunderbolt, but relented sufficiently to place him in the sky. Ophiuchus contains seven Messier objects M9, M10, M12, M14, M19, M62 and M107 - which are all globular clusters of stars. At right ascension 18 hours 28 m, declination 6 degrees 30 m (the upper left hand corner of the constellation) there is an open cluster of stars that is labeledNGC6633. From a catalogue compiled in 1888, called the "New General Catalogue" . An open cluster consists of a large number of stars, although not as dense as a globular cluster. M9 (NGC 6333) is the smallest of this group, unresolved except in large instruments. The cluster is found 3.5° SE of eta Ophiuchi. It is considered to be about 26,000 light years away. In the same field are two more globular clusters: NGC 6342 (1° SE) and NGC 6356 (1° NE). M10 (NGC 6254) and M12 (NGC 6218) are nearly identical globular clusters: like tiny explosions of stars with dense cores. M12 is eight degrees north of zeta Ophiuchi and two degrees east. M10 is 2.5 degrees SE of M12, with 30 Ophiuchi in the same field. M14 (NGC 6402) needs a 20-cm telescope to resolve; it's more condensed than the preceding two and slightly fainter. M19 (NGC 6273) is another very dense cluster, usually described as "oblate", or egg-shaped. It is about 25000 light years away. M19 is seven degrees due east of Antares in Scorpius, or two and a half degrees west of the bright double 36 Ophiuchi (and very slightly north, less than a degree). M62 (NGC 6266) is six degrees SW of theta Oph (and four degrees south of M19); this is another non-circular globular cluster, a little brighter than M19. (Note: Burnham includes this Messier in Scorpius; nearly all other authorities put it in Ophiuchus.) M107 (NGC 6171) is the faintest of the bunch and quite small. This is one of those "Messiers" that were added to the original list, for some reason. It's three degrees SSW of zeta Ophiuchi. B78, the "Pipe Nebula", is a naked eye dark nebula 2° southeast of theta Ophiuchi, in very rich area of the Milky Way. Barnard's Star is the most rapidly moving star relative to the solar system, and the second closest star to us, at a distance of only 5.91 light years. This is a red dwarf, with a visual magnitude of only 9.5, and consequently not easily found. The star is three degrees due east of beta Ophiuchus. A slight oscillation in both the right ascension and declination of Barnard's Star has led observers to suggest the possibility that one or more planets orbit the star. In the upper-left, less than 2 degrees north- east of Beta, is IC-4665, a beautiful open cluster that can be seen very well with ordinary binoculars.
The Pleiades New to the sky in late evening youll see the wonderful gem of an open cluster rising in the East. As Tennyson said "The Pleiads , rising thro' the mellow shade, Glitter like a swarm of fireflies Tangled in a silver braid...". Nearly every culture mentions the Pleiades in some respect. Chinese writings appear to mention it from 2357 BC. American Indian folklore of the Kiowa talks of the "Seven Maidens" who where protected from giant bears by their placement in the skies. To the Japanese, they are called Subaru.
Mercury is at its greatest elongation (separation) from the Sun on the morning (2.5h) of the 6th, October, 2009. This is an excellent opportunity to identify it.