The Sky by Seasons

December 21 - 27 December 28 - January 3 January 4 - 10 January 11 - 17 January 18 - 24 January 25 - 31 February 1 - 7 February 8 - 14 February 15 - 21 February 22 - 28 (or 29) March 1 - 7 March 8 - 14 March 15 - 21 March 22 - 28 March 29 - April 4 New year,new millennium,same stars 14 The second-brightest star in the night sky 26 Spring arrives 39 Finding true north 42 Finding true south 45 April 5 - 11 April 12 - 18 April 19 - 25 April 26 - May 2 May 3 - 9 May 10 - 16 May 17 - 23 May 24 - 30...

Familiarizing yourself with the night sky

Like our ancestors did thousands of years ago, it's quite natural for us today to view the night sky as an inverted bowl upon which the stars are attached and the Sun, Moon, and planets move. And it requires only a little imagination to further visualize that the inverted bowl of stars is actually the hemisphere of a globe - a celestial sphere - which we see from the inside out. Earth floats freely in space within this sphere, which lies at an immense but arbitrary distance. The sphere revolves...

The smile in the sky and the watery realm

Rising in the southeast this week around 7 o'clock, and well up by 8 30, is a faint wallflower of a constellation, but one that offers a big smile if you can find it. In fact, it is often referred to as the 'smile in the sky' Capricornus the Seagoat. This constellation has come down through the ages unaltered in form. In the ancient star atlases, Capricornus was depicted as a goat with the tail of a fish. The constellation resides in a region once known as 'the Sea.' But more on that later....

The Sun stands still

Summer officially arrives in the Northern Hemisphere this week, in the form of the summer solstice, the instant the Sun reaches its most northerly position for those living north of the equator. In the Southern Hemisphere, meanwhile, the Sun reaches its lowest point in their sky, hence this week marks the beginning of southern winter. On the first day of summer, the Sun is directly overhead at noon for people living at latitude 23.3 N, a region denoted as the Tropic of Cancer. There's nothing...

Stellar nomenclature

At least fifty of the brightest stars have names that are either of Greek or Latin origin (Sirius, Castor, Pollux), or Arabic (Altair, Fomalhaut). Many of the brighter naked-eye stars in the constellations, however, are designated not by name but by small letters of the Greek alphabet. In this system, introduced in 1603 by Johannes Bayer, the brightest star in a constellation generally is labeled Alpha or a, the second-brightest star is Beta or p, and so on down to Omega or ra. (There are...

Bootes the Herdsman

High overhead as darkness falls in the Northern Hemisphere these early summer evenings shines a lone, bright orange-hued star. Just go out and look almost straight up around 9 o'clock you can't miss it. This star is Arcturus, the luminary of the constellation Bootes the Herdsman. If you live in a suburban location, you can probably just make out the constellation's star pattern. It looks like an ice-cream cone with bright Arcturus at the cone's apex and the ice-cream end pointing more or less...

The flashing Dog Star

On a winter's evening, with the snow crunching beneath your boots and your breath hanging in frosty clouds in the air, your eye may catch upon a single star glimmering like a multifaceted diamond through the dark silhouettes of bare trees in the southeast. As you gaze upon this scene, you may imagine a kind of stillness settling upon the world, or perhaps within yourself. At such contemplative times it is hard to tell. But something about 'lone stars' strikes an emotional chord within us all....

Predicting moonrise

Many people get confused when it comes to predicting when and where the Moon will appear in the sky. Unlike the Sun, the Moon doesn't rise and set daily, nor does it appear in the same part of the sky on a nightly basis. Moreover, sometimes it appears in the the evening, while at other times it's in the morning. The Moon just seems all over the sky. Once you learn a few lunar basics, though, it is not difficult to master the comings and goings of our nearest neighbor in space. First, the Moon...

The Pleiades rise at sunset

Just before dawn in early June, a tiny dipper-shaped group of stars in Taurus can be seen shining faintly through the strong twilight. This event is the 'helical rising' of the Pleiades, the cluster's first appearance after coming from behind the Sun. For the rest of the year, the Pleiades rise earlier each day, mounting ever higher in the sky until this week, when they rise as the Sun sets and are in the sky all night. Look toward the east after sunset to see this distinctive nest of stars...

Finding true south

The Northern Hemisphere has the bright North Star as its guiding light to astronomers, navigators, surveyors, and Boy Scouts everywhere. Not so the Southern Hemisphere. The place in the sky toward which Earth's south polar axis points appears virtually starless. Except, that's not exactly true. Sigma (o) Octantis, which can just be seen with the unaided eye in a dark sky, is designated Polaris Australe, the South Pole star. Sigma, which resides in the dim constellation Octans the Octant,...

The seasonal lag

Winter, which usually arrives on or about December 22, never seems to be appropriately on time, no matter where you live. In the southern realms of the Northern Hemisphere, the first day of winter can be quite mild, even tropical, while in the north, cold air has been infiltrating since late September and several inches of snow may already be on the ground. Depending on where you live, you are either surprised that winter has snuck up on you or incensed that someone would make a big deal about...

Three star clusters

Auriga the Charioteer (January 25-31) holds more fascination than just ancient star myths. The pentagonal-shaped figure is home to a trio of bright star clusters that, under certain sky conditions, can be seen with the naked eye. Our galaxy contains hundreds of millions of star clusters, of which we can see mere thousands from Earth. Most star clusters are too faint to be seen without optical aid, but a handful can be glimpsed as misty patches between the stars. Lying in the star-thronged...

Five southern birds

Call it a starry roost or celestial aviary, but this week after sunset, five constellations representing exotic or mythical birds flock around the south celestial pole. Furthest north, and thus visible low on the southern horizon from mid-latitudes in the Northern Hemisphere, are Grus the Crane and Phoenix, the great bird that rose from the ashes of its predecessor. Three other birds lie closer still to the southern pole Tucana the Toucan, Pavo the Peacock, and Apus the Bird of Paradise. Of...

Who was Auriga the Charioteer

With the winter Milky Way mounting high in the sky in late January evenings, it is a good time to locate a bright constellation that represents both a star lore mystery and high mythological drama. I'm speaking of Auriga the Charioteer, a pentagonal figure that resembles either a squatty roofed house or a crude baseball home plate, whichever form you prefer. For people at mid-northern latitudes (30-40 N), Auriga is first seen early December evenings rising just after sunset, following first the...

The secondbrightest star in the night sky

One of nature's more pleasing coincidences is that the two brightest stars in the night sky - Sirius mag - 1.46 and Canopus mag - 0.72 - lie only 35 from one another - that's about three and a half fist-widths held at arm's length. What's not so pleasing, however, is that for many sky-watchers in the Northern Hemisphere Canopus never rises very high in the southern sky. Its peak altitude at latitude 36 N is only about 1 . To see Canopus, you're going to have to travel south. In Dallas latitude...