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  • Rapt in Awe

    My Journey through the Astronomical Year

    Think of this as a "companion text" to this, the main web site. Not required reading, butI hope you'll find it interesting and helpful.

Prime Time observing for November 2009

November brings us  our southern most – and northern most – guidepost stars,  Fomalhaut and Capella – as well as a nice meteor shower for early risers and, of course, the continuing dance of Jupiter’s moons.

I’ve also introduced two new features which should become a staple  – a downloadable black-on-white version of each chart  so printing one for use outside doesn’t drain all your color ink.  The second feature is to include on the chart a summary of the information worth remembering about each guidepost star. It’s much more fun if you really know a star – that is, what makes it distinctive – and not simply know how to find it.

For northern hemisphere observers Fomalhaut is the guidepost star we see for the least amount of time – and Capella is the one we see the most. In fact, for many Capella is visible  during some hours  every night of the year – and for those north of latitude 45 degrees it is circumpolar – that is, it never sets. But lonely – and newly fascinating  – Fomalhaut just puts in a relatively brief appearance low to the south.  That’s where we’ll start with a finder chart for Fomalhaut. Like our other finder charts it is centered on 45 minutes after sunset for mid-month, but should be useful throughout November.

famlhaut_finder_c

Click chart for a larger image. (Chart modified from screen shot of Starry Nights Pro software.)

(Click here to download  a black-on-white version of the preceding chart, suitable for printing in landscape format.)
hubble_sauron

Hubble image showing debris ring that surround Fomalhaut.

Fomalhaut is “lonely” because there are few bright stars in its vicinity. It is now of special interest because early in this century the Hubble Space Telescope got a fantastic picture of a disc of “debris” surrounding it, showing this young star to be in the throes of forming planets. Then in 2008 scientists announced they had actually found a planet circling Fomalhaut, the first planet outside our solar system to be seen with visible light. Cool! Add to this that Fomalhaut is a neighbor, just 25 light years away,  and in this photograph could be easily mistaken for Sauron of Lord of the Rings fame and Fomalhaut becomes quite memorable.

Finding Fomalhaut

As always, it’s easiest if you start looking  in the southeast 45 minutes after sunset when in the twilight only the brightest stars are visible as shown on our chart. Fomalhaut is the brightest STAR south of southeast and about a fist and a half above the horizon 45 minutes after sunset. I emphasize “star” because in 2009 Jupiter is in the vicinity further south, significantly brighter, and about twice as high.  Trailing well behind Fomalhaut – to the east – and lower still is a second magnitude star (same brightness as the North Star) called Deneb Kaitos. It’s about the same distance from Fomalhaut as Fomalhaut is from Jupiter and I mention it only so you won’t mistake it for Fomalhaut.

If you have learned the Great Square – see this post – then the two stars that form the western edge of that square can be used, as shown in our chart, as pointer stars. Drawing an arrow through those two stars leads you to Fomalhaut. You could also wait until a couple hours after sunset when you would find Fomalhaut very close to due south. Even then, from my latitude of 41.5° N it is not quite two fists (19°) above the southern horizon.

Ahhh Capella!

Capella is distinctive because it’s not “a” star – its two! But these two, bright, yellow suns are so close together that you’ll always see them as one, even if you use a large telescope. Together they make a star that rivals Vega and Altair , now well into our western sky, in brightness. (see Summer Triangle chart here.) In fact Capella is the third brightest star in the Northern Hemisphere – but that’s a tad deceptive because it doesn’t count Sirius – the brightest star that most Northern Hemisphere observers can see, because technically Sirius is in the Southern Celestial Hemisphere, since it is below the celestial equator.  But you don’t have to worry about such technicalities to enjoy a view of Capella. Just use the chart below which shows the view to the Northeast 45 minutes after sunset on November 15, but generally good for the entire month. You will need a very clear horizon, however, especially at the start of the month because then Capella will not even be one fist above the horizon.

Click image for a larger,c olor version of this chart.

Click chart for a larger image. (Chart modified from screen shot of Starry Nights Pro software.)

(Click here to download  a black-on-white version of the preceding chart, suitable for printing in landscape format.)

Capella is really a complex multiple star. It’s two main components are both yellow giants dubbed Aa and Ab, but there are two more stars in this family. However, they are a pair of red dwarfs only visible in a telescope and are so far away from the two bright stars that they take more than 1,000 years to complete an orbit. The two bright stars orbit in just 104 days.  James B. Kaler, in his book The Hundred Greatest Stars, says this about the Capella twins:

These two magnificent giants are separated by about the distance between Venus and the Sun. A resident on a ‘Jupiter’ ten times further out would see two ‘Suns’ about half a degree across (similar to the Sun in our own sky) , separated at maximum by some 6 degrees, one setting right behind the other.

So when you find Capella pause – picture yourself on the Jupiter-like planet with these twin yellow Suns in your sky!

Finding Capella

It’s easiest to find Capella if you start 45 minutes to an hour after sunset. Choose a spot with a clear horizon to the Northeast and watch for a bright star to appear very near the horizon. Like all bright stars near the horizon, Capella will twinkle and flash in different colors because you are seeing it through a lot of atmosphere. It won’t show its soft, golden hue until it is much higher in the sky.

For me Capella marks a graceful arc of  bright stars and asterisms that circle the north celestial pole.  If you have been following these directions for a few months, look at Capella, the Bow of Perseus, and the “W” pf Cassiopeia to see what I mean. Watching these move in the course of a single night – or from month to month – always gives me a real sense of how, from our vantage point, all the stars appear to circle Polaris. Other stars and asterisms introduced in previous months that are still readily seen include  the Summer Triangle of Altair, Deneb, and Vega, whichis high over head and crossing into the western sky. Arcturus is just above the horizon in the west, the Big Dipper just west of northa nd hugging the horizon, and the Teapot is diving intot he ground in the southwest.

Dancing moons . . .

Jupiter is in its prime on these November nights, and gets as high as you’ll see it this year when it crosses the meridian roughly 45 minutes after sunset, which is when I suggest you start your observing if you’re tying to learn the brightest stars. It’s also a good time to turn a good pair of binoculars towards Jupiter and see if you can spot any of its four Galilean moons.  These are easily bright enough to see in binoculars, but there are two problems. First, the glare of Jupiter can drown them out (they will look like faint stars very near the planet and roughly in line with its equator) and second, you need to hold your binoculars very steady.  Your best chance would be with 10X50 binoculars steadied against the corner of a building, or fence post, or whatever.

In September there was a special event where the four moons were all hidden at once. This post starts with that event, but gives lot more details about Jupiter’s moons. You might want to review it. Or, you  may just want to know which of Jupiter’s moons is where on any given night. In that case  use this neat little online utility provided by Sky and Telescope magazine.

. . . and “falling stars”

leonids_1833

Now that's a meteor shower!

The best meteor shower I ever saw came several years ago when early one morning Bren and I dragged some pillows and sleeping bags to the upstairs deck and tried to count the Leonids. Oh, it wasn’t like this old woodcut shows. That was a real shower and must have been something to behold. And sadly, the Leonids this year – at least for North American Observers – will not put on a great show, but you’ll certainly have a chance to see more meteors than usual.  Besides, November mornings can be refreshing and there are lots of other things in the morning sky this month, so why not take a peek – treat the unusual number of meteors you wil see as frosting on the cake!

The drawing on the right depicts the Leonid meteor shower of 1833  – as remembered 50 years after the event! I don’t believe the drawing is literal, but I do believe this was an extraordinary meteor shower.

When and where

The shower is predicted to peak on November 17,  at 4 am EST, or 9 hours Universal Time.

Look anywhere in the sky – though the meteors you see should trace back to a spot in the constellation Leo in the Eastern sky at that time. This spot is called the radiant and mared on the chart below. But don’t expectt o see meteors here. You’ll see them justa bout anywhere in the sky.

And yes, you may hear predictions about sharp, fantastic spikes with hundreds of meteors an hour. This is true, but these  spikes will be brief and they will come at a time that favors Asia. One prediction puts this peak at 21:43 Universal Time and the other 17 minutes later on November 17, 2009. I’m amazed that we now understand these showers so well that such predictions can be made.

. . . and what else?

But back to the morning of November 17, 2009. What can you expect your morning sky to contain, besides some bright meteors? Well, for starters, all the brilliant stars of late winter, but with two nice planetary additions: Saturn will be the bright “star” just one fist above the horizon and almost due east at that time. Well above it will be an even brighter Mars. In fact, the two planets bracket Leo the Lion whose head marks the radiant point for the Leonid meteors. And if you wait until well into morning twilight you’ll see a brilliant Venus rise a bit south of east.

leonids_chart

Click image for larger version.

(Click here to download  a black-on-white version of the preceding chart, suitable for printing in landscape format.)

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2 Responses

  1. Love this downloadable chart and summary, thanks! Caroline

  2. […] Oh my! And now with 100 years of scientific progress, the verdict is that Martha Evans and her causal observer friends were correct – and the “best authorities” wrong. Arcturus is the brightest. So much for my idea that you can’t tell the difference with the naked eye! Give it a try and see what you think. (You can find a chart for Capella and more details about that star in this post.) […]

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