The month of June has the shortest nights of the year (for northern hemisphere stargazers), but there’s still plenty to see if you wait till the sky gets dark after midnight.
Sitting high in the south – almost directly overhead – during June is the constellation of Hercules.
The body of Hercules is made up of four stars in an asterism known as The Keystone. The four stars in The Keystone, like all the star in Hercules, are not especially bright, so the pattern doesn’t stand out all that clearly. To find it draw a line from the bright orange star Arcturus to the bright white star Vega. Hercules sits about 2/3 of the way along this line.
Once you find the Keystone try and trace the four lines that come off each corner, Hercules’s arms and legs.
But the most interesting feature in Hercules is the faint fuzzy patch known as the Great Globular Cluster in Hercules, M13 (marked with a + above).
M13 lies on a line drawn between two of the stars of the Keystone, ζ and η Her. It’s just visible to the naked eye in dark sky conditions (which you won’t get during the summer months) but is easily found using binoculars. It will look like a fuzzy out-of-focus star.
In fact it is a globular (globe-shape) cluster of around 300,000 very old stars, orbiting our galaxy.
If you’ve got a powerful telescope then you should be able to make out individual stars within this cluster.
This evening, and for the next few evenings, just as the sky begins to darken after sunset, you’ve got a chance to see three of the five naked-eye planets side by side.
The two brightest naked eye planets (Venus and Jupiter) are close together, separated by only a few degrees, closing to 1° on 28 May (in what we call a conjunction). This should make them very easy to spot, low in the NW from around 30 minutes after sunset. In fact they’re close enough together that you could fit them both in one binocular field of view.
Mercury, however, might be trickier to spot. As the faintest naked-eye planet it will lurk in the twilight sky unseen for many people, just above the two brighter planets.
Remember, if you’re observing with binoculars or a telescope make sure you wait until the Sun has fully set
There’s a partial lunar eclipse tonight, visible from the UK, as well as from the rest of Europe, Africa, Asia and Australia.
It won’t be hugely dramatic, as it’s only a partial eclipse of the Moon, not a total one. Even total lunar eclipses are far less grand than total solar eclipses, unfolding over several hours rather than minutes, and turning the Moon a deep red rather than making it vanish altogether.
And for partial lunar eclipses, like tonight’s, all we’ll see is a slight darkening of the edge of the Moon, what we call the “limb”.
Nevertheless it’s worth watching out for if you have clear skies. And the best thing of all is that light pollution isn’t really an issue; you’ll see it just fine from a city.
Here are the timings:
Penumbral Eclipse Begins: 18:03:38 UT
Partial Eclipse Begins: 19:54:08 UT
Greatest Eclipse: 20:07:30 UT
Partial Eclipse Ends: 20:21:02 UT
Penumbral Eclipse Ends: 22:11:26 UT
Remember that these times are in universal time (UT) which is the same as GMT, so add one hour on for BST.
Best time to look is between 9pm and 9:20pm BST.
Image from NASA’s eclipse site.
The iconic Hubble Space Telescope (HST) was launched 23 years ago on 24 April 1990, and ever since has been returning breathtaking images of the cosmos as well as world-changing science. It is, without a doubt, one of the most successful scientific instruments ever built.
To celebrate its 23rd birthday here is a list of five stunning celestial objects visible over the next couple of months that you can find for yourself using a small earth-based telescope. Most of these objects will look like nothing more than diffuse grey smudges in the field of view of your eyepiece, but I’ve illustrated this post with some HST images of the same objects, to show you what they really look like. Despite the fact that your telescope can’t ever show anything as stunning as an HST image, there’s something even more wonderful about seeing these objects in real time, for yourself, not mediated via a computer screen.
Rising around 2030 local time at the end of April, and 1800 local time at the end of May, Saturn is visible in the evening skies throughout the Spring and into Summer. At the moment Saturn’s rings are tilted very favourably towards us, presenting a striking view. Through a very small telescope – or binoculars on a tripod – Saturn might appear as nothing more than a oval, or at best a circular disk with handles, but most modest telescope should show the disk of the planet and the rings, and even Saturn’s largest moon, Titan.
2. Sombrero Galaxy, M104
The stunning Sombrero Galaxy in the constellation Virgo gets to its highest above the horizon around 2330 in late April, and 2130 in late May. It’s one of the brighter galaxies in the sky, and so even a medium sized telescope should show up the dark dust lane obscuring the view of the central bulge of the galaxy. This dust lane is actually a ring that surrounds the galaxy, and is probably where most of the star-forming takes place, as it is composed of atomic hydrogen and dust.
3. Ring Nebula, M57
Located in the constellation of Lyra in the Summer Triangle, the Ring Nebula (Messier number 57) is a striking object in medium or large telescopes. It rises from low in the NE mid evening to almost directly overhead by the time dawn begins to brighten the sky. The Ring Nebula is a great example of a planetary nebula, so-called as it looks like the disk of a planet when seen through modest telescopes. However this name is completely misleading, as the gas in this nebula was puffed off by a red giant star just before it died and collapsed into a white dwarf, a fate that awaits the Sun in 5 billion years or so.
4. The Great Globular Cluster in Hercules, M13
This spherical collection of around 300,000 stars is one of the best examples of a globular cluster in the sky. It’s high in the SE sky during the evenings of April and May, and continues to be visible into the Summer. M13 is at the very limit of naked eye visibility, and small telescopes show it off beautifully. In fact, this is one object where a smaller earth-based telescope gives you a better overall view of the object than the mighty HST. Hubble has such a high magnification that its field of view is very small. This is fine when you’re looking for tiny faint galaxies millions of light years away, but a nearby globular cluster presents problems; it’s simply too big to fit into the field of view. Nevertheless, this spectacular HST image shows the heart of M13, and the stunning array of stars that make up this beautiful object.
5. The Eagle Nebula, M16
OK, OK, so maybe this is more strictly speaking a late summer object, but it is visible pre-dawn in late May, low in the south, in the constellation of Serpens. Despite the unsocial hours it keeps at this time of the year, it still has to be included in any top-5 list of Hubble objects. The iconic “Pillars of Creation” image, taken by HST in 1995, is one of the most widely viewed of all Hubble images. It shows giant pillars of gas within the Eagle Nebula within which new stars are being born. However it’s a pretty tricky nebula to see through a telescope. There’s a star cluster within it that you’ll make out even in light polluted skies but to see it best you’ll need to head to a dark stargazing site and be patient.
For maps and tips about how to find these objects, and hundreds more like them using binoculars or a telescope check out my book, Stargazing for Dummies.
UPDATE: I just realised; there are people alive today with degrees in astrophysics who weren’t yet born when the Hubble Space Telescope was launched in 1990!
Today marks the 175th anniversary of the birth of John Muir, the Scottish-born American naturalist, writer, and advocate for the preservation of wild land.
The protection of our wildernesses landscapes (defined as anywhere you cannot see the intrusion of human activity) is more important than ever, with the spread of suburbia and the urbanisation of more than 50% of the world’s population.
But one measure of what makes a wilderness has to-date been largely ignored: that of the darkness of the night sky. After all, if you can see the sky glowing orange at night then you are seeing the intrusion of human activity, and you can’t consider the land you’re in a true wilderness.
John Muir’s legacy as the founding father of the conservation movement lives on today, in part in the organisation The John Muir Trust.
The JMT estimates that the amount of Scotland’s landscape that is wilderness is rapidly diminishing, dropping from 31% of Scotland to 28% between 2008 and 2009, but I think if you added in the spread of man-made light pollution the situation would be decidedly worse.
I am fortunate to have been awarded the JMT’s Bill Wallace award to help fund a trip later this year (once the skies get dark again after the bright summer nights) to map light pollution in one of Scotland’s most wild landscapes, between the JMT properties of Quinag and Sandwood Bay.
Hopefully this project – the first of its kind in this remote area – will shed some light on the problem of the loss of our wilderness nightscapes.
Head outside during April just as the sky gets properly dark and sitting high in the south is the constellation of Leo the Lion.
Leo is well-known as it’s one of the signs of the zodiac, and therefore one of the constellations through which the planets, Sun and Moon pass over the course of the year.
Leo is also well-known due to its most prominent feature, a pattern of stars within the constellation (called an asterism) known as The Sickle, which looks like a backwards question mark, with the bright star Regulus as the dot.
Regulus is known as the king star, and is one of the brightest stars in the sky, shining blue-white in late winter and spring.
Within the constellation of Leo are two groups of galaxies, marked as 1 and 2 on the chart above.
Enjoy the spring skies, and happy galaxy hunting!
Maps and descriptions like this one for each of the 88 constellations can be found in my new book, Stargazing for Dummies. Click on the image on the right for more info.
To celebrate International Dark Sky Week I’m giving away a signed copy of my book, Stargazing for Dummies!
For a chance to win a copy, tweet “#stargazing @darkskyman …” followed by your best stargazing memories.
The competition is open to all my followers on Twitter for the duration of Dark Sky Week 5-11 April 2013, and I’ll draw the lucky winner at random some time on 12 April.
Here is a selection of some of your stargazing memories so far:
Today, Sunday 17 March 2013, it is the Spring Equilux throughout the UK (and possibly elsewhere too*) meaning that there are almost exactly 12 hours between sunrise and sunset.
This date differs from the Spring, or Vernal, Equinox (1102 GMT on Wednesday 20 March 2013) for a variety of reasons, which I explain in a previous post but here is a list of sunrise / sunset times for a variety of towns and cities throughout the UK:
|Town / City||Sunrise||Sunset|
As you can see the time between sunrise and sunset is not exactly 12 hours everywhere but this is the day of the year when that is closest to being true everywhere*. Yesterday the sun rose a couple of minutes later and set a couple of minutes earlier, and tomorrow the sun will rise a couple of minutes earlier and set a couple of minutes later, as the days lengthen.
Also, the reason that sunrise and sunset do not occur at the same time everywhere* is due mainly to the longitude of the town; the further east a town is the earlier it sees the sun in the morning, and the earlier it loses it again at night.
So happy Equilux everyone*!
* interestingly, the equilux does not occur on the same same day for everyone, it depends on your latitude. The closer you are to the equator the earlier the date of your equilux. For example the equilux in most US cities occurred yesterday, 16 March, and in cities near the equator there is never a day with exactly twelve hours between sunrise and sunset! Take Quito, the capital city of Ecuador (latitude 0 degrees 14 minutes south) for instance. The length of day there only ever varies between 12 hours and 6 minutes long and 12 hours and 8 minutes long!
Over the next few weeks UK stargazers will have a chance to see a bright comet in the western sky at sunset.
The comet is called PanSTARRS C/2011 L4, or PanSTARRS to its friends, and was named after the PanSTARRS 1 (Panoramic Survey Telescope and Rapid Response System) telescope in Hawaii, which was the telescope used to discover the comet in 2011.
Since then Comet PanSTARRS has been nearing the Sun, heating up, and forming a long bright tail as the surface ices on the comet sublimate into gases.
Comet PanSTARRS has been visible in the southern hemisphere for a while now, but it’s only now that northern stargazers will get a chance to see it.
Over the next week you’ll probably need binoculars to see it, but it may brighten to become a naked eye comet later this month.
Here’s a star map showing where it will be in the sky over the next month:
This star map shows the view looking west just after sunset. The red crosses mark the path of the comet as it climbs in the sky, and the red numbers mark out the date in five day intervals, with 10 Mar being lowest on the map, then 15 Mar, 20 Mar, 25 Mar, 30 Mar, and finally 5 Apr. The horizontal line shows the horizon at 7pm in mid March, but the stars in this map will set earlier and earlier as we go into April. Put simply, you need to go and look west just as the sky begins to darken after sunset.
How best to see Comet PanSTARRS
There are a few tips to help you maximise your chances of seeing this comet:
1. Find an observing location with a clear western horizon (the west coast is ideal, but higher ground inland would be fine too).
2. Do your best to get away from very bright lights and out of city centres, where the horizon is normally built up anyway.
3. On 12 and 13 Mar the thin crescent Moon passes close to the comet, making it a little easier to find.
4. Don’t expect too much! The comet, even if it brightens as expected, will always appear low on the horizon, and in twilight, making it quite difficult to spot. Binoculars can really help you locate it.
News reports have recently come in of a huge meteor exploding in the air over the Russian cities of Yekatarinburg and Chelyabinsk (about 200km apart), injuring hundreds of people. It’s worth clarifying some of the facts in this matter:
The object that exploded was a meteor, a lump of space rock passing through the Earth’s atmosphere. In this particular case the meteor appears to have exploded around 10km above the ground, over the city of Chelyabinsk.
The shockwave from the explosion damaged some buildings, shattered windows, and set off car alarms. It appears that most of the injuries came from the broken glass, not from the meteor itself hitting anyone.
Showers of fragments from the meteor have been reported too, falling after the explosion over a large area of Russia.
The meteor poses no risk to us any more; it’s all burned up, and it was a one-off random event. Such things are not that rare, happening once every few years, but this one just happened to fall over a populated area.
This meteor was unrelated to asteroid 2012 DA14 that is due to pass by the Earth later today.
UPDATE: A 6m diameter crater has been found in the ice & snow of Lake Chebarkul where the meteorite is thought to have landed: