“What’s that bright star in the east,” a friend asked recently?
“Early in the evening?” I queried. “Yes.”
“Got to be Jupiter!”
And, of course, it is. But wait, there’s more! To the naked eye Jupiter is a dazzler. This month it shines at magnitude -2.8 and is in the company of two other dazzlers, Capella (magnitude 0.06) and Aldebaran (magnitude 0.84).
Jupiter also can teach you something about our journey around the Sun – how stars and tend to rise about a half hour earlier each week. In our charts below we show Jupiter on November 1, November 15, and November 30. In each case it is roughly 10 degrees – one fist – above the horizon – but each chart is for an hour earlier – the first for three hours after sunset, the second for two, and the last for one hour when Jupiter will still dazzle in the dying evening twilight.
But the real fun with Jupiter this month is to use your binoculars to try to spot the four Galilean Moons – Io, Europa, Ganymede and Callisto – his “court.” And whether or not you can do that, be sure to turn your binoculars on two nearby star clusters – the Hyades, just 153 light years away, and the incomparable Pleiades, about 400 light years away – and yes, keep those distances in mind as you look and you will realize that the two clusters are roughly the same size, but distance makes one appear smaller, though no less brilliant with its hot, young stars. (Be sure to click on the following charts for a larger version. These are all made by modifying Starry Nights Pro screen shots.)
Galileo always gets his name associated with Jupiter’s Moons because in 1610 he turned his telescope on them and published his results – but he didn’t get to name them. Well, he tried. He called them the “Medicean Stars” after grand duke of Tuscany Cosimo II de’ Medici and Cosimo’s three brothers. But that didn’t stick, instead, as Rosaly Lopes tells us in her wonderful Sky and Telescope article on planet names in the November 2012 issue, Simon Marius a German astronomer, discovered them independently and at the urging of the famous Kepler applied the names that have stuck with these four moons. Jupiter actually has 67 moons at last count, but you aren’t going to find the others in your binoculars. These are the big ones that even Galileo’s primitive telescope revealed.
So how do you go about seeing them yourself? Well don’t simply swing your binoculars up there and expect to see them. Maybe with your bright, young eyes you can. But most likely you’ll have to work at it a bit. Take your time. They are close to Jupiter and generally lost in its glare. But with patience you should find one or two – and if you don’t see them after a little effort, then the problem probably is that you aren’t holding your binoculars steady enough. Try holding them against a tree, the corner of the house – anything for support. Ideally you would mount them on a tripod and in many places they sell mounts such as this for doing just that – well worth the small investment, by the way, and these little mounts work with almost all binoculars.
Another tip – do make sure your binoculars are in sharp focus. Many casual binocular users don’t know how to do this – they simply turn the center focusing knob. but that just gives you a good rough focus. For most of us our two eyes are not exactly the same, so to focus a binocular so it works best for you, do this:
Close your right eye and focus with the center knob using only the left eye and left side of the binocular. Once the image is sharp there, close the left eye and use the diopter adjustment on the right eyepiece to bring that side into focus. ( You usually turn the right eyepiece to make this diopter adjustment.) From that point on you should be able to focus those binoculars by using just the center focus – but if you try another pair, you’ll need to adjust them for your eyes in similar fashion.
And what exactly can you expect to see? Up to four star-like objects on a rough line with the equator of the planet. You may only see one or two depending on how close they are to the planet.
Which is which? To learn that, go here and use the excellent little java script utility to tell you which Moon is where at any given time. With binoculars you want the right-side up view. With small telescopes it is much easier, of course, to see these Moons, but a telescope will change the orientation and this script allows you to change that orientation to match your telescope’s view.
Is there any other planetary action this Month? Yes – but Jupiter is the main show. Saturn, Venus, and Mercury all make a nice appearance in the morning twilight near the end of the month. And Mars is setting in evening twilight – or nearly so.
In the early morning hours of November 17 there should be an excess of meteors – about 20 hours – from the Leonid Meteor Shower. This shower has from time to time yield a much more spectacular show, but right now it is in a down period. The Geminids in December should be much better.