October 24th to 28th: Observe the planet Uranus
October is still a good month to find the planet Uranus. With a magnitude of +5.8 you might even be able to spot it with your unaided eye, and it is an easy object in binoculars. It lies is Pisces about 15 degrees below the eastern side of the Square of Pegasus as shown on the chart. With a small telescope you may even see that it has a disk - now around 3.7 arc seconds across - which is a very attractive blue-green colour.
October 24th - 28th : Search for Neptune - with no Moon in the sky.
Neptune reached opposition on August 22nd and so, with a magnitude of 7.8 it should be easily seen in binoculars under a dark evening sky. It lies roughly due south at 9pm GMT towards the end of October when there is no Moon in the sky a few days before new Moon. Neptune lies about 1.6 degrees above the star Iota Aquarii as shown on the chart. Iota Aquarii can be found by moving 5 degrees to the left and slightly upwards from the star Delta Capricorni. Neptune is now very close to its discovery position in 1846 and completed its first orbit since discovery on July 11th.
Around October 21st: the Orionid Meteor Shower
Though the Orionids are not one of the most spectaculer showers with peak rates around 20 per hour, they are interesting as it is believed that the meteors originate from Comet Halley. It is worth looking out for them for a week around the 21st as the shower is long lived. Sadly, a waning gibbous Moon will hang in the East hiding the fainter trails. They will best be seen in the hours before dawn when Orion is high in the southern sky. The star chart shows where they appear to radiate from - called the radiant - at the upper left of Orion, close to the boarder with Gemini. Its best to look almost vertically where the sky is most transparent. The Halley meteors are amongst the fastest and enter the upper atmosphere at ~41 km per hour and often leave what are called persistant trains - streaks of ionized gas as the incoming dust particles burn up in the atmosphere. Halley's Comet actually gives us two meteor showers per year as we intersect its orbit twice as the Earth orbits the Sun. The other is in May and the shower is called the Eta Aquarid shower.
Find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum
In the late evening, the galaxy M31 in Andromeda is visible in the south-east. The chart provides two ways of finding it:
1) Find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye. The photons that are falling on your retina left Andromeda well over two million years ago!
2) You can also find M31 by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right as shown on the chart.
Around new Moon (19th - 31st Oct) you may also be able to spot M33, the third largest galaxy after M31 and our own galaxy in our Local Group of galaxies. It is a face on spiral and its surface brightness is pretty low so a dark, transparent sky will be needed to spot it using binoculars (8x40 or, preferably, 10x50). Follow the two stars back from M31 and continue in the same direction sweeping slowly as you go. It looks like a piece of tissue paper stuck on the sky just a bit brighter than the sky background. Good Hunting!
1) Find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye. The photons that are falling on your retina left Andromeda well over two million years ago!
2) You can also find M31 by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right as shown on the chart.
Around new Moon (19th - 31st Oct) you may also be able to spot M33, the third largest galaxy after M31 and our own galaxy in our Local Group of galaxies. It is a face on spiral and its surface brightness is pretty low so a dark, transparent sky will be needed to spot it using binoculars (8x40 or, preferably, 10x50). Follow the two stars back from M31 and continue in the same direction sweeping slowly as you go. It looks like a piece of tissue paper stuck on the sky just a bit brighter than the sky background. Good Hunting!
October 1st and 2nd: Mars and the Beehive Cluster
As October begins, Mars, in Cancer, lies within the Beehive Cluster M44 and stays within it until the 2nd. A very nice telescopic sight but you need to get up at around 5 am!
08/10/2011 - A possible Draconid meteor storm
What could well be the most spectacular celestial event this month will occur on the night of October 8th. That night, the Earth will cross the orbit of the comet Giacobini-Zinner. With the well known meteor showers such as the Perseids and Leonids, debris released from the comet as it rounds the Sun has had time to spread right around its orbit, so a meteor shower is seen each year. But in this case, the dust from the comet has not yet spread far round the orbit, so we only expect to see a significant number of meteors - known as the Giacobinids - once every 13 years. As the debris has not yet had time to disperse there is a chance of seeing what is called a "meteor storm" when the meteor rate could reach into the thousands per hour as was seen in 1933 when the peak rate exceeded 100 per minute or 6,000 per hour. In 1946, the meteor storm reached a similar rate and was observed by radar from Jodrell Bank in Cheshire. This October we again have a chance to see a significant meteor rate with the peak expected to be in the evening of Saturday the 8th between 8pm and 10pm BST. If its clear, get to a location with a good low north-western horizon as darkness falls! The radiant of the shower is, as their name implies, in the constellation Draco, the dragon, which will be at a reasonable elevation in the north-west during the evening. Unfortunately, there will be a waxing gibbous Moon in Aquarius so making the dimmer meteors impossible to see.
08/09/2011 - Supernova Visible from Earth
A star exploding millions of light years away will be visible to amateur skywatchers across Britain this week for the first time since a supernova in the 1950s.Amateur stargazers will be able to witness the most visible exploding star since 1954 in skies above Britain this week.
The cosmic event is one of the closest stellar explosions to Earth since 1987, and is the nearest example of its type to be seen from Earth in 40 years.
The exploding star, named PTF-11kly, is predicted to reach its brightest between September 9 and 12 and will visible in clear skies all over Britain.
Supernovae can help scientists measure the size and age of the universe and a team of scientists at Oxford University are tracking the explosion using the Hubble Space Telescope.
Dr Mark Sullivan, the astrophysicist leading the Oxford team examining the supernova said: "This is accessible to anyone with a decent pair of binoculars. For many it could be a once in a lifetime chance to see a supernova blossom and then fade before their eyes. We may not see another like it for over 100 years."
It will appear blueish-white just above and to the left of the last two stars in the Plough in the Ursa Major constellation.
Observers are advised to stay away from street lights for maximum visibility.
The supernova was first spotted by astronomers in California.
The discovery was made in what was believed to be the first hours of the rare cosmic explosion using a special telescope at the Palomar Observatory near San Diego and powerful supercomputers at a government laboratory in Berkeley, US.
The detection so early of a supernova so near has created a worldwide stir among astronomers, who are clamouring to observe it with every telescope at their disposal, including the giant Hubble Space Telescope.
Scientists behind the discovery at the Lawrence Berkeley National Laboratory and the University of California at Berkeley say the extraordinary phenomenon – labelled by the rather obscure designation PTF 11kly – will likely become the most-studied supernova in history.
"It is an instant cosmic classic," said Peter Nugent, the senior scientist at UC Berkeley who first spotted it.
PTF 11kly occurred in the Pinwheel Galaxy, located in the Ursa Major constellation, better known as the Big Dipper. At a distance of roughly 21 million light years, that puts it, on a cosmic scale, practically "in our backyard," Nugent said.
By comparison, most supernova found with the 48-inch Palomar telescope are about 1 billion light years away and far too faint for the general public to see, Nugent said.
Initially detected on August 24, the PTF 11kly has literally grown brighter by the minute and was already 20 times more luminous in just one day.
It is expected to reach its peak sometime between September 9 and 12, when it will become visible to stargazers using a good pair of binoculars or small telescope.
It will appear, bluish-white, just above and to the left of the last two stars in the Big Dipper handle.
"There are billions of stars in a galaxy. This supernova will outshine them all this weekend," Nugent told Reuters.
Supernovae of this type, classified as a "Type 1a" event, occur when a superdense white dwarf star, about the size of Earth but containing somewhat more mass than our own sun, explodes like a gargantuan thermonuclear bomb.
The blast hurls matter in all directions at nearly one-tenth the speed of light – matter that ultimately will form the building blocks of other stars and planets.
Such events, accounting for about one in five of all supernovae, are also used by scientists in measuring the expansion of the universe.
Similar supernovae are known to have occurred in the Pinwheel Galaxy at least three times before – in 1909, 1951 and 1970. But instruments available to observe this one are far more sophisticated, and its early detection is giving scientists an unprecedented glimpse of such phenomena.
For astronomers, the royal straight flush of supernovae are those occurring in our own galaxy, which last happened in 1572 and was visible with the naked eye for months, Nugent said.
Records from antiquity indicate that an even more spectacular supernova in the Milky Way lit up the sky in 1006 A.D., Nugent said.