Thursday 25th November, 2010
Get yourself outside tonight if it’s clear, pull up a deck chair, and scan the star clusters, nebulae, and even see another galaxy with your binoculars. They are just perfect for some objects like the larger open clusters. Just aimlessly wandering along the band of the Milky Way is also very enjoyable. If you have binoculars up to 10 x 50 then they’re ideal for the job, portable, and easy to hold. Anything over this size will usually need a tripod. All the objects listed here are at their best in dark skies, ideally with the bright Moon not around.
The Moon tonight…waning gibbous 73% full, rising in NE at 7.53 pm, and setting in NW at 11.36 am (GMT) (26th)
The Sword of Orion, and M42
Rising in the east tonight is the impressive constellation of Orion The Hunter, a sure sign of winter. It’s a striking constellation with the unmistakable, straight line of the three stars of Orion’s belt. Now look below the belt and you’ll see Orion’s Sword. To your naked eye it looks like a line of three fuzzy stars that hang down from the belt, resembling a sword. But when you look through your binos you will see that this is actually a group of star clusters, not individual stars. Notice how the middle cluster glows, especially with averted vision. What you are looking at is the famous, and probably most photographed deep sky object ever, the Orion Nebula or M42. This object is a huge and complex region of gas clouds, around 14 light years across. This place at 1,500 light years away is a vast stellar nursery, but it’s just one small part of an even larger region of gas that spans nearly the entire constellation. New stars, solar systems in formation, and even freely floating planets have all been observed in the Orion Nebula.
Tonight the Orion Nebula rises in the east at 8.01 pm, climbs highest in the south at 1.33 am (GMT), and sets in the west after sunrise.
The Orion Nebula can even be seen with the naked eye under very good skies, it is a magnitude 4.0 object
How long will it be around for? The Orion Nebula is in a winter constellation. So it will slowly and gradually move across the sky eventually sinking into the west by the end of March, when it will make way for the spring constellations rising in the east.
The Pleiades, or Seven Sisters
Rising in the north east tonight in the constellation Taurus is the one open cluster that lots of people can name and recognise, the Seven Sisters, The Pleiades, or M45. It lies between Perseus and Orion, and to the east of Auriga. You can easily see it naked eye, as a large fuzzy patch of stars. M45 is a close open cluster at just 440 light years away, it’s one of the nearest and so appears large in the sky. The stars in the cluster are also very young at only around 150 million years, and the brightest ones you can see are also the very youngest and hottest. The “Seven Sisters” cluster actually contains up to 1,400 members.
This attractive open star cluster fits nicely into your binoculars field of view, providing a very satisfying sight especially in dark skies with the Moon absent.
Tonight the Pleiades Cluster rises in the north east at 3.14 pm, it gets to its highest point in the south at 11.24 pm (GMT), and sets in the north west after sunrise.
The Pleiades Cluster is at magnitude 1.6
How long will it be around for? The Pleiades too will be visible in the sky with the Orion Nebula until around the end of March.
The Andromeda Galaxy, M31
High in the eastern sky tonight is the famous Andromeda Galaxy, or M31. It is a huge spiral galaxy 2.5 million light years away, with up to one trillion stars, and a diameter of up to 220,000 light years…more than twice the size of our Milky Way. You can even see Andromeda naked eye as a fuzzy glow, and there are two main ways to find this island universe in the sky. One is to locate the large square of Pegasus with its four stars marking each corner. You’ll find Pegasus to the east of Perseus, and Cassiopeia. The star at the upper left of the square is called Sirrah (or Alpheratz), look to the left of Sirrah and you’ll see three stars in a line, a dimmer star and two bright stars. The first bright star is Mirach. Now look above Mirach and you’ll see a dimmer star, look about the same distance above again from the dimmer star, and here is located the Andromeda Galaxy (M31). Another way to find M31 it is to use the right hand V of the W of Cassiopeia and imagine a line pointing down, this V points just to the left of Andromeda.
Get your binoculars on M31 and you’ll see the bright core of the galaxy as a small fuzzy blob. But keep studying and use averted vision, and you’ll soon start to make out the fainter shape of the galaxy’s disk extending out from the core. This is an object far outside the Milky Way, an entire ”island universe”. To be seen at its best Andromeda should be observed with the bright Moon absent under dark skies, but it’s still visible even from urban areas.
Tonight the Andromeda Galaxy is rising from in the east after dusk, it’s virtually directly overhead at 8.44 pm (GMT), and eventually sinks low in the north west before sunrise. It is circumpolar, meaning it never sets in northern latitudes.
M31 is at magnitude 3.4
How long will it be around for? The Andromeda Galaxy is actually circumpolar from northern latitudes. It is nicely high in the sky now but will gradually sink to its lowest point just above the horizon in the north in mid March, before starting its rise again.
The Perseus Double Cluster
This cluster is one of my favourites, it looks stunning in a telescope at low power, but binoculars also show it well. The Perseus Double Cluster, NGC 884 and NGC 869, or H and X Persei are actually two seperate open star clusters close to each other in space at around 7,000 light years away. They are only a few million years old, much younger than the Pleaides. To find it I could tell you to find this star, draw a line to that star etc, but the easiest way I have found to locate the Perseus Double is just to look for a fuzzy irregular patch in the band of the Milky Way between Cassiopeia and Perseus, (cluster marked as H+X on Perseus map). Once you see it, get your binos on it and you’ll see two very attractive open clusters of sparkling stars set against the blackness of space. There’s also a nice line of stars that curves away from the upper most cluster, when you see this line of stars you’ll know you have this popular deep sky object in your view.
Tonight you’ll see the Perseus Double Cluster rising from the north east after dark and getting very high in the sky to the east. It is circumpolar meaning it’s always above the horizon and never sets.
This open cluster is a magnitude 4.00 object
How long will it be around for? The Perseus Double Cluster will always be above the horizon, but by April it will have moved over to the north and much lower in the sky.
Jupiter and its moons
Jupiter the giant of the solar system is on show right now, although it is gradually on the wane as far as size and brightness go, having passed full opposition in mid September. But the solar system’s most massive planet and its collection of four main moons can be seen in binoculars. Look to the east after it goes dark and the brightest “star” you see is Jupiter. Put your binoculars on it and although the disk of the planet is small, look carefully and you should see four tiny pinpoints of light around it. These are the moons of Jupiter, Ganymede, Callisto, Io, and Europa. Jupiter’s moon Io is the most volcanic place in the entire solar system, and Europa is covered in ice with an ocean below its frozen crust. One of those four pinpoints of light you see (Europa) has more water on it than all of Earth’s oceans put together, and could even have extraterrestrial life living there. Ganymede is the largest moon in the solar system, even bigger than Mercury, and Callisto could also have a subsurface ocean. The moons shift and change postion over mere hours, so it’s a continually changing scene.
Tonight you’ll see Jupiter quite high in the south east by night fall, it rises highest in the south at 7.33 pm, and sets in the west at 1.08 am. (GMT)
Tonight Jupiter is at magnitude -2.44
How long will it be around for? Jupiter will eventually go out of sight in the setting Sun’s glow by March 2011.
The Beehive Cluster, M44
The Beehive Cluster, Praesepe, M44, or NGC 2632 is a very nice and attractive open star cluster to look at through your binoculars, and does kind of look like a swarm of bees. The Beehive is another open cluster close to Earth, at 577 light years away in the constellation of Cancer. This puts it slightly further away than the Pleaides. M44 rises from the north east, and you’ll see it with your naked eye as a nebulous patch on clear moonless nights. This cluster lies in the fainter constellation of Cancer, in between Leo, and Gemini. The stars that make up the head of Leo the Lion look like a large backwards question mark. You’ll find M44 with your naked eye roughly half way between this “question mark”, and the two twin stars of Castor and pollux in Gemini. The Beehive actually has over 1,000 stars, and is around 600 million years old.
This is really one for the early hours at the moment, as you’ll have to wait until beyond midnight if you want to get a good view of the Beehive Cluster. Tonight it rises from the north east at 8.41 pm (GMT), and climbs to its highest point in the south just before sunrise. Viewing this object gets more convenient in the coming weeks though, as it gradually rises earlier.
This object is at magnitude 3.7
How long will it be around for By April when M42 and the Pleiades will be sinking into the western horizon, the Beehive Cluster will still be nice and high in the sky in the south. But by June it will have disappeared below the north west horizon by nightfall.
The Hyades Cluster
Look to the eastern sky, to the lower left of the Pleaides Cluster, and you’ll see the bright orange star Alderbaran. Alderbaran is an orange giant, and marks the eye of the bull in the constellation Taurus. Alderbaran marks the position of the closest star cluster to Earth, the Hyades. This star grouping of up to 400 members is large and loose, due to its closeness at a mere 151 light years away. This open cluster is so spread out that even your binoculars will just about get all of its stars in their field of view. But this is a really nice collection of suns to gaze at through your binos on crisp dark nights. It contrasts well with bright Alderbaran, although this orange giant is not actually a member of the Hyades Cluster, being much closer to Earth at 65 light years away.
Tonight the Hyades Cluster rises from the east at 4.44 pm, and gets nice and high in the south at 12.38 am (GMT), eventually sinking towards the western horizon before daybreak.
How long will it be around for? The Hyades Cluster will be on view until March/April. At this time it will be close behind the setting Sun, following it into the western horizon.
…also check out Planets To See In The Sky Tonight