FRIDAY, NOVEMBER 11
■ The waning gibbous Moon rises less than an hour after nightfall is complete, with Mars shining to its upper right as shown below. A week ago it was Jupiter's turn with the Moon, and three days before that it was Saturn's. The Moon doesn't play favorites; it makes a point of visiting each planet every month, not to mention its own phase-maker, the Sun.
■ Saturn is at eastern quadrature today, 90° east of the Sun. Therefore, a telescope shows the black shadow of Saturn's globe on the rings as wide and prominent as the shadow ever gets.
Do you know why? The answer is at the bottom of this page.*
SATURDAY, NOVEMBER 12
■ Spot bright Vega in the west in early evening. Its little constellation Lyra extends to its left.
Somewhat farther left, about a fist and a half at arm's length from Vega, is 3rd-magnitude Albireo, the beak of Cygnus. This is one of the finest colorful double stars for small telescopes: yellow and pale blue. Ukraine star?
Farther along in roughly the same direction you come to 3rd-magnitude Tarazed and, just past it, 1st-magnitude Altair.
SUNDAY, NOVEMBER 13
■ The late-rising Moon (it comes up around 9 p.m.) shines under Pollux and Castor, as shown above.
■ The slow, steady drizzle of the Taurid meteor shower continues this week. Its meteors are few; current reports are running at about a half dozen per hour seen by practiced meteor counters under excellent conditions. But the Taurids produce an unusual number of bright fireballs — occasionally, extremely bright. And this year there are predictions that fireball activity may be greater than usual.
So if you see a bright, relatively slow meteor this week, trace its path backward across the sky and see if the line intersects Taurus. If so you probably saw a fragment of the Taurid parent body: the unusual short-period comet 2P/Encke.
MONDAY, NOVEMBER 14
■ Vega is the brightest star high in the west. Close by it are three interesting double stars for binoculars and telescopes.
Just above Vega, spot 4th-magnitude Epsilon Lyrae, the Double-Double. Epsilon forms one corner of a roughly equilateral little triangle with Vega and Zeta Lyrae. The triangle is less than 2° on a side, hardly the width of your thumb at arm's length.
Binoculars easily resolve Epsilon. And a 4-inch telescope at 120× or more should, during good seeing, resolve each of Epsilon's wide components into a tight pair.
Zeta too is a double. This pair is much closer and appears single in most binoculars, but a telescope plainly resolves it.
Delta Lyrae, upper left of Zeta by a similar distance, is a much wider and easier binocular pair. Its stars are reddish orange and blue.
TUESDAY, NOVEMBER 15
■ Jupiter's Great Red Spot should transit the planet's central meridian around 8:25 p.m. Eastern Standard Time. Timetables of all the Red Spot's transits this month, and all of the interplays between Jupiter and its moons and their shadows, are in the November Sky & Telescope, page 51.
WEDNESDAY, NOVEMBER 16
■ The last-quarter Moon rises around 11 p.m. Once it's well up, look for the Sickle of Leo to its left and lower left, not quite enclosing it.
Skywatchers in the longitudes of the Americas will find the Moon forming an equilateral triangle with the Sickle's two brightest stars: Regulus below the Moon and Gamma Leonis to the Moon's lower left. The triangle is about 8° on a side.
The Moon was exactly last quarter at 8:27 a.m. this morning.
■ Two bright stars, same distance. Vega is the brightest star high in the west. Shining from 25 light-years away, Vega is a fast-rotating type-A star, larger and hotter than the Sun. We see it almost pole-on.
Now turn to the south. From bright Jupiter, look about three fists lower right. There's Fomalhaut. It too is a hot A star, but it looks only a third as bright as Vega. In this rare case, that's because it really is one third as luminous. Because Vega and Fomalhaut are the same distance from us: 25 light-years.
Lined up between them, counting left from Vega, are Altair and Saturn. Altair is 17 light-years away. Saturn, a totally different creature, is currently 81 light-minutes away.
THURSDAY, NOVEMBER 17
■ The Leonid meteor shower, which has been sparse in recent years, just might put on a show in the early-morning hours of Friday the 18th for eastern North America. Meteor-shower analyst Mikhail Maslow predicts a possible outburst of up to 250 or 300 meteors per hour visible starting around 1 a.m. EST Friday morning (6:00 UT), good timing for this region. And the farther east you are the better. The shower's radiant, near the Sickle of Leo, will be well up by then for the East Coast and will climb higher into dawn. The light of the Moon, a day past first quarter, will interfere to some degree.
FRIDAY, NOVEMBER 18
Orion clears the eastern horizon by about 8 or 9 p.m., depending on how far east or west you live in your time zone. Upper left of Orion, bright Mars glares. Look similarly far upper left of Mars, and there's Capella.
High straighter above Orion are Aldebaran and, higher still, the little Pleiades cluster, the size of your fingertip at arm's length.
Down below Orion, Sirius rises around 10 or 11 p.m. Sirius always follows two hours behind Orion, or equivalently one month behind Orion, as they wheel through the night and through the seasons.
SATURDAY, NOVEMBER 19
■ Whenever Fomalhaut is "southing" (crossing the meridian due south, which it does around 7 p.m. this week), the Pointers of the Big Dipper stand upright low due north, straight below Polaris.
Also at that time, the first stars of Orion are soon to rise above the east horizon (for skywatchers in the world's mid-northern latitudes). Starting with the rise of Betelgeuse, it takes Orion's main figure about an hour to completely clear the horizon.
■ Algol in Perseus should be at its minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 10:25 p.m. EST.
This Week's Planet Roundup
Mercury and Venus are hidden in the glare of the Sun.
Mars, magnitude –1.6 in eastern Taurus, clears the east-northeast horizon around the end of twilight and gains altitude through much of the night. Once it's up in view there's no missing it; Mars now outshines even Sirius (which rises around 9 or 10 p.m.). Mars's fiery yellow-orange color helps give it away.
Mars is passing between the horntips of Taurus, Beta and fainter Zeta Tauri, moving westward. Mars shines exactly between Beta and Zeta on Sunday the 13th.
Mars-colored Aldebaran, only an eighth as bright at magnitude +0.9, sparkles to Mars's upper right by 15°, about a fist and a half at arm's length. Just a little farther to the planet's lower right is Mars-colored Betelgeuse. But color perception in astronomy can be tricky. Read "Seeing the True Colors of Mars," a lesson for astronomers from a chemist, in the November Sky & Telescope, page 52.
In a telescope Mars is now about 16.5 arcseconds wide, almost the 17.2 arcseconds it will display around its closest approach to Earth on December 1st. Its opposition comes on the night of December 7-8, when the Moon will occult Mars for much of North America and Western Europe! Map and timetables.
Jupiter blazes white high in the southeast in twilight at magnitude –2.8. It's highest in the south as early as 8 p.m. now, in dim Pisces. In a telescope it shrinks a bit this week, from 46 to 45 arcseconds wide.
Saturn, magnitude +0.7 in Capricornus, glows highest in the south as twilight fades. As night progresses, it moves lower toward the southwest and sets around 10 or 11 p.m.
Uranus, magnitude 5.6 in Aries, is just past opposition. It's up in the east in good binocular or telescope view by mid-evening, displaying a tiny, very slightly blue-greenish gray disk 3.8 arcseconds wide. It a telescope at high power it's obviously non-stellar. See the Uranus finder charts in the November Sky & Telescope, page 49.
Neptune, magnitude 7.9 at the Aquarius-Pisces border, is high in the evening 6° west of Jupiter. It's just 2.3 arcseconds wide, again non-stellar in a telescope but requiring a more effort than Uranus. It's slightly bluish gray. See the Neptune finder charts in the September Sky & Telescope, page 49.
All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions and graphics that also depend on longitude (mainly Moon positions) are for North America.
Eastern Daylight Time, EDT, is Universal Time minus 4 hours. Eastern Standard Time, which begins Sunday morning November 6th, is UT minus 5 hours. (Universal Time is also called UT, UTC, GMT or Z time.)
Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
This is an outdoor nature hobby. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential magazine of astronomy.
Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or Jumbo Edition), which shows stars to magnitude 7.6.
Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many. The next up, once you know your way around, are the even larger Interstellarum atlas (stars to magnitude 9.5) or Uranometria 2000.0 (stars to magnitude 9.75). And be sure to read How to Use a Star Chart with a Telescope. It applies just as much to charts on your phone or tablet as to charts on paper.
You'll also want a good deep-sky guidebook. A beloved old classic is the three-volume Burnham's Celestial Handbook. An impressive more modern one is the big Night Sky Observer's Guide set (2+ volumes) by Kepple and Sanner.
Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically, meaning heavy and expensive. And as Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."
Audio sky tour. Out under the evening sky with your
earbuds in place, listen to Kelly Beatty's monthly
podcast tour of the heavens above. It's free.
"The dangers of not thinking clearly are much greater now than ever before. It's not that there's something new in our way of thinking, it's that credulous and confused thinking can be much more lethal in ways it was never before."
— Carl Sagan, 1996
"Facts are stubborn things."
— John Adams, 1770
* Answer to why Saturn's shadow on the rings appears widest at quadrature: It's because when we see an outer planet 90° from our line of sight to the Sun (at quadrature), the angle between the sunlight illuminating the planet and our line of sight to the planet is the greatest it ever gets. So, we see as far around into the planet's night side as we ever can.
For the same reason, quadrature is when Mars appears its most gibbous, when Jupiter's east and west limbs appear lit their most unequally, and when the eclipses of Jupiter's moons into and out of Jupiter's shadow occur farthest away from Jupiter's limb.
Extra bonus points: Can you prove why quadrature is when this happens? Calling geometry whizzes! If you come up with a proof, please post it or a link to it in the comments here. A shortcut: Although the planets' orbits are slightly elliptical, you can treat them as circles centered on the Sun for this purpose. Comparing the time of quadrature to the exact time of a planet's minimum phase angle (angle of illumination) in an almanac shows that the circular-orbit shortcut is quite good enough for practical purposes.