With the full moon been and gone (Monday the 20th), and having endured some pretty awful weather lately (and not much astronomy), I have to say I’m looking forward to the next couple of weeks, really hoping for some dark and clear nights. The fact that it doesn’t get dark until nearly midnight, however, which may be too late for some, does raise the question of what is there to observe while the night’s still young.
Planets and stars
The moon will still be around in the evening sky for a little while longer, of course, but as the sky begins to darken from about 10pm, the first things you’ll notice are the planets: Mars and Saturn (both due south), and Jupiter (low in the West). Mars and Saturn will continue to visible throughout the summer, but Jupiter, passing into the west, won’t be visible for much longer in the evening sky – so check it our while you can!
The first stars to appear in the evenings will probably be the zero magnitude Vega (high in the East) and Arcturus (high in the south west). The brightest star in the constellation Lyra, Vega lies around 25 light years away, and is the fifth brightest star in the northern hemisphere, it’s a lovely blue colour (it’ll appear a very bright white to the naked eye, but binoculars/telescopes will reveal the bluish tint). Arcturus, 36 light years away in the constellation Boötes, is a red giant, the orangey-red colour being obvious, even to the naked eye.
Below and west of Arcturus is Spica, a first magnitude star in Virgo. Actually a close binary system, the main component is a blue giant. Like Vega, the blue/white colour will be obvious in binoculars/telescopes.
Due east, and below and to the right of Vega, is Altair, 17 light years away in the constellation Aquila (the Eagle). White in colour, Altair is one of the closest first magnitude stars, and comprises one corner of what’s called the ‘Summer Triangle’ (the other vertices being Vega and Deneb). The latter (1.25 mag, 2600 light years away in Cygnus) is one of the most luminous stars known, in the region of 200,000 times the brightness of our sun. Its distance has, therefore been difficult to ascertain. Cygnus lies in the East at around 10pm, just below and to the left of Vega. That Deneb appears so bright, given its distance, is a testament to its scale.
Directly to the South, in the constellation of Scorpius (so below Saturn and Mars) lies the red supergiant Antares. This really is a whopper! Orangey/red to the naked eye, it has a radius approximately 883 times that of the Sun. Were it at the centre of our solar system, the star would extent beyond the orbit of Mars! Like the red supergiant Betelgeuse in Orion, Antares will explode in a supernova at some point in the next couple of hundred thousand years, and, when viewed from the Earth, will be visible during the day!
Later in the night …
Those up later will be treated to the awe-inspiring summer Milky Way, extending from Cassiopeia in the North, down through the Summer Triangle, to Scorpius and Sagittarius in the South, where there are a number of objects that I’m particularly looking forward to observing again. Starting with M11 (the Wild Duck cluster) this is a spectacular open star cluster in the constellation of Scutum (the Shield). Easily visible with binoculars, this is a lovely, and very sparkly cluster, and is well worth a visit.
Below and to the right of M11, in the constellation of Serpens, lies M16 (the Eagle nebula, home to the famous ‘Pillars of Creation’). Although visible in binoculars, you’ll really need a telescope to see the famous pillars, photographed by the Hubble Space Telescope some years ago. Of all the objects in the night sky, I find this one especially fascinating, and the scale of the thing mind-blowing. Check out M16’s Wikipedia page for more information.
M17 (the Omega or Swan nebula) lies just below M16, and is one of the brightest and densest star forming regions in the galaxy. It’s easily visible in binoculars, as is M20 (the Trifid nebula – Trifid as in three-lobed, not the man-eating plants of sci-fi literature) below it. There’s so much to see facing South at this time of year (open clusters, globular clusters, star fields, nebulae …). So, grab a pair of binoculars and go out for a look. I, personally, can’t wait!
What’s up?
As already discussed, there’s lots to see in the South at this time of year. However, if we turn our backs on the centre of our galaxy for a little while, why not have a look for the Andromeda galaxy in the Northeast (below and to the right of Cassiopeia). Although still pretty low in the sky, it will be rising earlier and earlier over the coming weeks, and is already visible in binoculars. To the right of Andromeda you’ll find the giant square of the constellation of Pegasus, and, to the right of that are M15 and M2, two of the finest globular star clusters in the night sky.
Clear skies!
Kevin Quinn is an amateur astronomer based in Cerne Abbas. He is the proud owner of a ten-inch reflector, a small refractor, a case of eyepieces, and a couple of pairs of binoculars. He tweets via @CerneAstro, and blogs via theastroguy.wordpress.com.
©Kevin Quinn
