European Association for Astronomy Education

Source: NASA

Western view of the horizon after sunset on May 16th, 2010. Created with Stellarium.

This weekend, Venus and the crescent Moon are gathering in the western sky for a spectacular conjunction, and they’re not alone. The International Space Station and, very likely, space shuttle Atlantis will join them for a rare four-way meeting of spaceships and planets over many locations. (read more)

This week is an excellent opportunity to see all the five “naked eye” planets in one night of observation.

You need to start about an hour after sunset by looking relatively low on the western horizon, you should be able to make out both Mercury and Venus, Mercury being the lower and fainter of the pair. You then need to look almost directly above your head to spot Mars – with it’s reddish hue you shouldn’t miss it. Saturn can be found by looking towards the east (to your left); if you have a telescope take a look, even a small instrument should show the famous rings. For the final of the five planets, Jupiter, you need to wait until the morning and take a look low on the eastern horizon about an hour before sunrise.

As the month progresses there will be some interesting encounters to watch out for – Venus and the Pleiades, the Moon and Saturn, Mars and the Beehive………. So keep reading the blog for more information.

The Sky literally brings together the Earth during GAM-be part of a global peace chain!

For the last of our late winter early spring constellations, let’s take a look at Leo, the Lion.

Leo is one of the constellations that actually looks reasonably like what it’s supposed to represent.

The brightest star of this constellation, alpha Leo, is called Regulus (meaning: the little king), it’s a blue-white star and when viewed with binoculars or small telescopes a fainter companion star of can be seen.
At the tip of the lion’s tail the blue-white star beta Leo, or Denebola, viewed through a telescope beta Leo seems to have an orange companion, but actually the two stars are far away from each other – it is an “optical” double as opposed to a real double star system.

Another excellent double is the binary gamma Leo, or Algieba (the lion’s mane), this pair, consists of a orange-red giant and a yellow giant, a small telescope is sufficient to split gamma Leo into the single stars.

Leo contains many bright galaxies, of which Messier 65, Messier 66, Messier 95, Messier 96, Messier 105, and NGC3628 are the most famous.

Have an enjoyable lion hunting safari!!

Image credit John Walker

If you are looking for something interesting today this coming weekend why not try a Messier Marathon. A Messier marathon is an attempt, usually organized by amateur astronomers, to find as many Messier objects as possible during one night. The Messier catalogue was compiled by French astronomer Charles Messier during the late 18th century and consists of 110 relatively bright deep sky objects (galaxies, nebulae, and star clusters). For more information take a look here www.richardbell.net/marathon.html or here http://deepskymap.org/ or even here http://en.wikipedia.org/wiki/Messier_marathon.

Happy hunting!

Image credit: SEDS, the Students for the Exploration and Development of Space,

Now that the moon is out of the way in the evening sky, take the opportunity to find some of the late winter, early spring constellations. If you have been looking at the sky regularly and at the same time each night (21h00 is a good time), you will have noticed that Orion has slowly “drifted” to the right (west) and its position has been replaced by other stars. The constellations that will dominate this part of the sky for the next month or so are Gemini (The Twins), Cancer (The Crab) and Leo (The Lion), all three being constellations of the Zodiac.

All three are interesting, but not all are easy to find; Gemini is very easy to find, just look for the two bright stars called Castor and Pollux. They represent the heads of the twins, while fainter stars sketch out two bodies; although Cancer the Crab is one of the more famous constellations, it is mostly made of dim stars; Leo’s head and mane are formed by an asterism known as the Sickle which looks like a backward question mark, one of the brightest spring stars, Regulus being at the base of the question mark.

Try to find these constellations in the sky and over the next few postings will take a look at some of the interesting objects that can be seen with a pair of binoculars or a small telescope – double stars, star clusters, galaxies ……….

If you enjoy worldwide astronomy events, watch out for Global Astronomy Month (GAM), running throughout April of this year. The GAM motto is “One People, One Sky” and it’s an opportunity to connect with people around the world.

For more information take a look here: www.astronomerswithoutborders.org/index.php?option=com_content&view=category&id=99&layout=blog&Itemid=149
Image credit: Astronomer’s Without Borders

Note: this post is adapted from Weekend SkyWatcher’s Forecast by Tammy Plotner on Universe Today, http://www.universetoday.com/

If you are ready for a challenge why not try spotting 11.8 magnitude Comet Tritton! Now cruising through the constellation of Aries (RA 1h 53.5m Dec 17° 39′), this faint fuzzy won’t be the easiest of targets to spot – but then it wouldn’t be a challenge, would it? Comet 157P Tritton was discovered by Keith Tritton (U. K. Schmidt Telescope Unit, Coonabarabran) on February 11, 1978. Now, almost 32 years later to the date, it’s back again on its every 6.33 year journey around our Sun. Although it won’t reach perihelion (closest position to the sun) until February 20, its original estimated return brightness was only expected to reach magnitude 16 and now it is far exceeding expectations. Don’t expect to see a flaming ball exhibiting a tail because that’s not going to happen… but congratulate yourself if you can find this faint fuzzy in the sky.

Image credit: Universe Today

If your skies are clear tonight, January 29, take advantage of one of the sky watching highlights of the year. A full Moon and Mars will be putting on a show, and the pair will be prominently close to each other in the sky. Plus, this Friday night’s full Moon is the biggest and brightest full Moon of the year. It’s a “perigee Moon,” as much as 14% wider and 30% brighter than other full Moons you’ll see later in 2010.

If you have a camera try taking a photo of this full moon and then the next couple of full moons (you’ll need to make sure you keep the camera “settings” the same each time); you should be able to see the difference in the “apparent” diameters .

For more information take a look here: www.universetoday.com/2010/01/28/

Image credit: Universe today – McDonald Observatory

Find the constellation of The Plough (also known as the Big Dipper, the Saucepan or the Wagon depending on which country you are in) and take a look at the second star of the “handle” of the saucepan; you should be able to make out a second, fainter, “companion” star. The two stars are sometimes called the “Horse and Rider,” in fact the ability to resolve the two stars with the naked eye is often quoted as a test of eyesight.

Many of the stars in the sky are in fact double stars (or even triple or quadruple stars), although not as easy to see as the example above. Many, however, can be seen in a small telescope or even in a pair of binoculars.

What is particularly interesting (and often quite spectacular) is the fact that many of the double stars are often two different colours, yellow and green, or orange and blue for example.

Here are a couple of double stars relatively easy to find.

The Pole star (Polaris) is a very easy double and can be seen in any small instrument
Rigel the bright star bottom right in the constellation of Orion is also easy

In another post we’ll look at some double stars a little more difficult to find, but when you find them or show them to others you will undoubtedly here “wow”!

Photo credit: Wikipedia

Did you get to take a look at the stars? Here’s what you should have seen, Betelgeuse (top left of Orion) is a reddish star, Rigel (bottom right of Orion) is a bluish star, Aldeberan (found by the following the imaginary line through the “belt” upwards to the right) has a distinct orange tint to it and Sirius (found by the following the imaginary line through the “belt” downwards to the left) is white – yes there are white stars! There are also yellow stars, green stars and stars of almost all the colours of the rainbow!

So why are stars different colours? In short it’s linked to their temperature, blue and white stars being extremely hot and red and orange being somewhat cooler, although still very hot!

If you would like to know more about the colours, temperatures and sizes of stars, take a look here: http://en.wikipedia.org/wiki/Star

If you asked someone what is the colour of the stars, they would probably say white; they wouldn’t be completely wrong; however, not all stars are white.

Go and take a look at the stars we have been talking about in previous posts; Betelgeuse (top left of Orion), Rigel (bottom right of Orion), Aldeberan (found by the following the imaginary line through the “belt” upwards to the right) and Sirius (found by the following the imaginary line through the “belt” downwards to the left).

Take a good careful look at these stars and in a future post we’ll talk about their colours!

If you cannot get out to observe because of bad weather don’t forget the second session of the project “From the Big Dipper to the Southern Cross” on the 10th of January, the project intends to bring the two hemispheres together – truly One People, One Sky! For this project there will be two telescopes – one in the northern hemisphere and one in the south – on two different nights. No experience is needed. This is a chance to watch as an experienced telescope operator and guide show how they capture the wonders of the night sky. Join other members of AWB Affiliates around the world. Chat will be available between participants and with the telescope operator. Join in or just watch – should make excellent armchair astronomy!

For more information take a look at http://www.astronomerswithoutborders.org/.

If you are looking for something relatively easy to show to people why not try Melotte 20 (also known as Collinder 39); this is an open cluster centred around the star Alpha Persei (or Algenib), the brightest star in the constellation of Perseus.

The cluster can be seen with the naked eye if you have a really dark sky, otherwise a pair of binoculars will show it in all its glory.

For more information about Melotte 20, take a look here: www.seds.org/messier/xtra/ngc/alphaper.html