BAS - MONTHLY SKY GUIDE November 2018 November is a great month to explore the Magellanic Clouds in the southern sky and the Andromeda Galaxy in the northern sky. And everywhere in between too. The summer constellations of Taurus and Orion are also rising in the east and lobbying for your attention. 1
DARK SKY BEST OBSERVING DATES - NOVEMBER At the beginning of November the Sun sets at 6:06pm but astronomical twilight does not end until around 7:30pm, so our night are getting shorter. By the end of the month astronomical twilight does not end until around 8:00pm. On November 1 st the Moon rises after midnight, so this is the start of our best observing period which runs through to just after the New Moon when the sliver of Moon sets early in the evening and casts little light into the sky. So, clear you calendar for the period November 1 st to 9 th. 2
Taurus USEFUL TELESCOPE ALIGNMENT STARS Alignment Stars: Aldebaran Rigel Orion In the eastern and north eastern sky we have two very prominent stars that make great telescope alignment stars. Aldebaran is bright yellowish star in the easily recognisable Taurus constellation. To the east we have the 7 th brightest star in the sky and brightest star in the Orion constellation, Rigel. These stars are easy to find and difficult to mistake for other stars. 3
CONSTELLATION OF THE MONTH PHOENIX Observing target: Robert s Galaxy Cluster - NGC 87 Phoenix constellation lies in the southern sky. It was named after the phoenix, the mythical bird that rises from its own ashes, and was first depicted on a celestial atlas by Johann Bayer in his 1603 Uranometria. Phoenix contains at least ten stars with known planets and does not have any Messier objects. There is one meteor shower associated with the constellation, the Phoenicids, which occurs around December 5 every year. The only observing targets in Phoenix are galaxies. One challenging target is Robert's Quartet, composed of the irregular galaxy NGC 87, and three spiral galaxies NGC 88, NGC 89 and NGC 92. The group of four galaxies is located around 160 million light-years away and are in the process of colliding and merging. The Phoenix constellation also contains possibly one of the oldest stars yet discovered, HE0107-5240. It has around 1/200,000 the metallicity that the Sun has and hence must have formed very early in the history of the universe. With a visual magnitude of 15.17,it is around 10,000 times dimmer than the faintest stars visible to the naked eye and is 36000 light years distant. 4
THE PLANETS Uranus Neptune Mars We only have one of the bright planets visible now, Mars, as its heads for the western horizon. However, patient planet hunters can be rewarded with glimpses of distant Uranus and Neptune. The faint blue dots can be found in Pisces and Aquarius respectively. At this time Uranus will be about 20 astronomical units from the Sun and Neptune about 29 astronomical units. 5
NEW MOON - 9 PM MERIDIAN CONSTELLATIONS Pisces Pegasus A couple of constellations in the sky along the meridian at about 9 PM during the New Moon period are Pisces and Pegasus. Pegasus is another of the 48 constellations catalogued by the Greek astronomer Ptolemy in the 2nd century. However Ptolemy, and astronomers before him, must have struggled to concoct a horse from the widely scattered stars of the constellation as only the front half of the flying horse is depicted. It was named after Pegasus, the winged horse in Greek mythology. Legend suggests Pegasus is a white winged horse that sprang from the neck of the Gorgon Medusa when Perseus beheaded the snakehaired monster. Pisces, another of the Ptolemy constellations, lies in the northern sky and its name means the fish (plural) in Latin. The constellations depicts two fish, one swimming to the west and the other to the north. Pisces dates from Babylonian times. The Babylonians saw it as a pair of fish joined by a cord. The constellation is usually associated with the Roman myth of Venus and Cupid, who tied themselves with a rope and transformed into fish to escape the monster Typhon. The star Alpha Piscium, also known by the traditional name Alrescha, the cord in Arabic, marks the knot of the rope. 6
NGC 7814 PEGASUS Stephan s Quintet An excellent object to search for in Pegasis is Stephan s Quintet is a group of five galaxies, NGC 7317-7320, first discovered by the French astronomer Édouard Stephan in 1877. They lie about 280 million light years from Earth. Four of the five galaxies were the first compact galaxy group ever discovered. The brightest galaxy in the group is NGC 7320, which is only 40 million light years distant. Another galaxy worth seeking out is edge-on spiral galaxy NGC 7814. The galaxy is sometimes called the little sombrero because of its resemblance to the Sombrero Galaxy (Messier 104) in Virgo. NGC 7814 has an apparent magnitude of 11.6 and is approximately 40 million light years distant. It appears as a small streak in the telescope eyepiece. 7
PISCES NGC520 M74 Pisces is all about galaxies, galaxies and more galaxies. One worth searching for is NGC520, the Whirligig Galaxy. This is a pair of interacting and merging galaxies 91Mly distant. Galaxy M74 is also worth a try. While it is a reasonably large face-on spiral galaxy it has low surface brightness and needs a good dark sky to be observed. 8
MAGELLANIC CLOUDS SMC LMC This is a great time of year to observe or image the Large and Small Magellanic Clouds. These satellite dwarf galaxies of the Milkyway are respectively about 160,000 and 200,000 light years from our solar system. While most observers of the Small Magellanic Cloud tend to focus just on the massive globular cluster 47 Tucanae, there are a host of nebulae, open star cluster and tiny distant globular clusters to observe across the galaxy. Similarly, the drawcard of the Large Magellanic Cloud is the Tarantula Nebula. But you can spend hours of observing time just wandering from nebula cloud to cloud and star cluster to cluster in the LMC. 9
ANDROMEDA GALAXY M31 This is also a good time to observe the Andromeda Galaxy, Messier 31, in the low northern sky. But be prepared to be less impressed by this galaxy than the show provided by the Magellanic galaxies. While northern hemisphere observers list M31 as one of their showcase objects, it is a little less inspiring for us. Its 2.5Mly distance makes its internal features and structure less than prominent. Its low position in the northern sky also creates atmospheric extinction and distortion problems for us in the southern hemisphere. But it is still worth some telescope time. 10
BUILD YOUR OWN OBSERVING LIST Click Find Objects Select object types Select constellation Search https://dso-browser.com/ Make sure you take a look at the great observing planning tool DSO-Browser before the New Moon period. This is a fantastic tool to help you build a list of objects you can try and find each month. Just a few clicks on www.dso-browser.com can generate a fantastic observing list of object types you are interested in. 11
AVOIDING CLOUDS www.cloudfreenight.com www.skippysky.com More info: http://philhart.com/content/cloud-forecasts-australian-astronomers And the find the best cloud-free evenings for observing make sure you check CloudFreeNight and Skippysky as you plan your next observing evening. 12