With Jupiter now returning to prime time for viewing (currently rising around midnight) amateur astronomers will be turning their view to this old favorite and it’s four large moons. But with just one glance you’ll notice something has changed. Normally, Jupiter’s two large cloud belts are easily visible through even a modest telescope. But when you look now, you’ll only see one. The South Equatorial Belt began fading late last year, and since May has all but disappeared. This sort of thing has happened before, most recently in 2007 when the belt faded slightly. And in the past the belt has always come back, often making a rather dramatic return. As scientists don’t completely understand the mechanism that causes this, there’s no sure way to know when the belt will be back. But based on precedent, it could be anytime in the next two years. Until then, enjoy a slightly different view of our solar system’s largest planet.
Something is Missing….
By July 17th, 2010, underGamma Delphini
By July 5th, 2010, underThere are a lot of good binary pairs out there, and one of the best is in the often overlooked constellation Delphinus. Gamma Delphini is easily found at the “nose” of this little constellation. It has a magnitude of 4.27 and is about 101 light years away. And it is made up of a yellow-white dwarf star and and orange subgiant. There is speculation that the orange subgiant may harbor a planetary system. So the next time you’re exploring the Summer Triangle, just look a bit to the east for this binary treat.
Red and Blue
By June 6th, 2010, underTonight the red planet Mars will make a nice pairing with Regulus, the blue-white star that is the brightest in Leo. With Mars currently at magnitude 1.2, it will be similar in brightness to magnitude 1.35 Regulus. While the pairing will be easily visible to the naked eye, a telescopic view will show the color contrast more easily.
Coma Star Cluster
By May 14th, 2010, underWhen we think of astronomy, we usually think of peering through a telescope at some faint fuzzy out in deep space. But the good news for beginners who may not own a telescope is that some deep sky objects are best seen through a pair of binoculars (which really are just a pair of small telescopes anyway.) One such object is the Coma Star Cluster (officially known as Melotte 111) in Coma Berenices. At a distance of 288 light-years, this open cluster is close enough to cover more than five degrees of sky. With only about 40 stars, it’s not one of the more densely packed clusters. But the good news is that a dozen or so of the stars are bright enough to be seen even from light polluted areas.
Finding the Coma Star Cluster is easy as it lies almost halfway between two bright stars. Start with Denebola, the bright star at the “tail” of Leo, and look toward Cor Caroli. The Coma Star Cluster will be right in between. If you’re not sure which star is Cor Caroli, look toward the end of the Big Dipper’s handle when moving away from Denebola. Cor Caroli will be about two thirds of the way to Alkaid, the star at the end of the handle.
M5 in Serpens Caput
By May 3rd, 2010, under
Globular clusters can be among the most beautiful objects in the night sky, and I rarely miss the chance to see one. Well situated for viewing this time of year is M5 in Serpens Caput. With a diameter of roughly 165 light-years, M5 is one of the larger known globular clusters. And at magnitude 5.8, it’s also bright enough to show some nice detail.
Bright Arcturus is a good starting spot for a star-hop to M5. Imagine a line to the southeast to delta Ophiuchus. A little to the side of that line will be alpha Serpens. At around magnitude 2.7, both of these stars are much dimmer than Arcturus, but are still bright enough to be easily found. M5 can be found roughly across the line from alpha Serpens. It’s not one of the more exact star-hops, but it doesn’t need to be. Once you’re in the area, M5 should show up nicely in your finder scope, giving you the chance to enjoy this bit of deep sky beauty.
Arc to Arcturus
By April 24th, 2010, underEvery amateur astronomer (or at least those without GoTo scopes) understands the importance of being familiar with the constellations and bright stars of the night sky. These are the signposts that let us “star-hop” our way to faint fuzzies we’re trying to find. One of the most important signposts, high in the night sky at this time of year, is an orange giant star called Arcturus. With a visual magnitude of −0.05, Arcturs is the brightest star in the constellation Boötes and the third brightest star in the night sky. Follow the arc of the Big Dipper’s handle toward the south, and bright Arcturus will be quickly found. Continue following the same arc to the south and you’ll come to Spica, a blue giant, and the brightest star in the constellation Virgo. This path gives rise to the old saying “Arc to Arcturus, then speed on to Spica.” If you’re an experienced amateur astronomer, this path is well known. If you’re just learning, or would like to learn, try to follow the arc tonight and learn two of the main signposts in the night sky.
One of the Pinwheels
By April 14th, 2010, under
High in the northern sky, just a little above the handle of the “Big Dipper,” is the grand spiral galaxy M101. As we can see it face-on, M101 is one of several galaxies sometimes called the “Pinwheel Galaxy.” M101 is a large galaxy, nearly twice the size of the Milky Way, and is estimated to be about 27 million light years away. Despite being so large and having a magnitude of 7.86, M101 appears quite diffuse and so isn’t an easy target for smaller telescopes. But if you have dark skies and a nice big Dob, this pinwheel is worth checking out.
The April Lyrids
By April 6th, 2010, underAfter more than three months without a good meteor shower, the Lyrids will reach their peak on April 21 and 22. Although typically a slow shower with only about ten or so meteors per hour, the Lyrids will occasionally have brief outbursts of more than ten times that rate. Although the moon could interfere earlier in the night, it will be low in the west during the peak viewing hours closer to morning.
Mercury Evenings
By April 6th, 2010, underLow in the western horizon, just after sunset, is a nice pairing of planets. Easily visible is the always bright Venus. But just to it’s right is the usually more elusive planet Mercury. A bright magnitude -0.2, and being near the even brighter Venus, makes this an excellent opportunity to see our solar system’s innermost planet. At the same time, high in the south in the constellation Cancer, the planet Mars is visible. And in the southeast in the constellation Virgo, you can see Saturn. It’s not often you can see four out of the five naked eye planets at the same time. But if you have a clear view of both the east and west horizons the next few nights, you’ll get your chance.
Cancer’s Second Cluster
By February 25th, 2010, under
Last time we took a look at M44, the Beehive Cluster, in Cancer. But M44 isn’t Cancer’s only cluster worth seeing. There is also M67, just a little to the south. At magnitude 6.9, it makes a very nice telescopic target. One difference between M67 and Cancer’s more famous cluster is that M67 is about six times as distant. With Mars still in the area and showing up nicely, this is still a very interesting part of the sky.