Chart for the whole sky in March Stars and planets in the March evening sky
Chart for the southern sky in March Interesting objects in the March southern sky
Chart for the north sky in March Interesting objects in the Summer North Sky
Sirius is the brightest star in the evening sky, northwest of overhead. Canopus, the second brightest star, is southwest of overhead. Orange Mars is low in the north. Saturn, medium-bright, is level with similar-looking Spica, low in the eastern sky. The Pointers and Crux, the Southern Cross, are midway up the southeast sky. The Scorpion rises in the southeast later.
Sirius is the first star to appear at dusk, northwest of overhead. It is quickly followed by Canopus, southwest of the zenith, then orange Mars low in the north. Below Sirius are Rigel and Betelgeuse, the brightest stars in Orion. Between them is a line of three stars: Orion's belt. To southern hemisphere star watchers, the line of three makes the bottom of 'The Pot'. Orion's belt points down and left to a Vshaped pattern of stars making the face of Taurus the Bull. Further down and left, low in the northwest, is the Pleiades or Matariki star cluster, setting early.
Sirius, 'the Dog Star', marks the head of Canis Major the big dog. A group of stars above it make the dog's hindquarters and tail. Sirius is the brightest star in the sky both because it is relatively close, nine light years away, and 23 times brighter than the sun. Procyon, between Sirius and Mars, marks the smaller of the two dogs following Orion the hunter across the sky. Procyon is seven times brighter than the sun and 11 light years away.
Mars is bright and orange above the north skyline. We passed by Mars in late January. It is slowly fading as we leave it behind. At mid month it is 130 million km away and small in a telescope. Left of Mars are Pollux and Castor, marking the heads of Gemini the twins. Above and right of Mars is the Praesepe cluster, marking the shell of Cancer the crab. Praesepe is also called the Beehive cluster, the reason obvious when it is viewed in binoculars. It is 500 light years away.
Rigel, above and left of Orion's belt, is a bluish supergiant star, 40 000 times brighter than the sun and much hotter. It is 800 light years away. Orange Betelgeuse, below and right of the line of three, is a red-giant star, cooler than the sun but much bigger and 9 000 times brighter. It is 400 light years from us. The handle of "The Pot", or Orion's sword, has the Orion Nebula at its centre; a glowing gas cloud many light-years across and around 1300 light years away.
The V-shaped group making the face of Taurus the bull is called the Hyades cluster. It is 130 light years away. Orange Aldebaran, Arabic for 'the eye of the bull', is not a member of the cluster but merely on the line of sight, half the cluster's distance. The Pleiades cluster, impressive in binoculars, is 400 light years from us. Its stars formed around 100 million years ago.
Crux, the Southern Cross, is in the southeast. Below it are Beta and Alpha Centauri, often called 'The Pointers'. Alpha Centauri is the closest naked-eye star, 4.3 light years away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light years away. Canopus is also a very luminous distant star; 13 000 times brighter than the sun and 300 light years away.
The Milky Way is brightest in the southeast toward Crux. It becomes broader lower in the southeast toward Scorpius. Above Crux the Milky Way can be traced to nearly overhead where it fades. It becomes very faint in the north, right of Orion. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one.
The Clouds of Magellan, LMC and SMC are high in the south sky, easily seen by eye on a dark moonless night. They are two small galaxies about 160 000 and 200 000 light years away. The larger cloud is about 5% the mass of the Milky Way galaxy, the smaller cloud 3%.
Saturn in the east at dusk. It is a little brighter than Spica, the brightest star in Virgo, on Saturn's right. Saturn's rings are nearly edge on to us this year. They look like a thick line through the planet. Saturn is 1280 million km away in mid March.
Brilliant Venus is beginning a slow rise into the western evening sky as it catches up on us from the far side of the sun. It might be seen near the west horizon soon after sunset, setting half an hour after the sun. At the end of the month Mercury will be just below Venus but a lot fainter.
Chart produced by Guide 8 software; www.projectpluto.com. Labels and text added by Alan Gilmore
The chart shows the southeast sky. Interesting star clusters and nebulae are indicated with asterisks. They are described below.
Large and Small Clouds of Magellan (LMC and SMC) appear as two luminous clouds, easily seen by eye in a dark sky. They are galaxies like the Milky Way but much smaller. Each is made of billions of stars. The Large Cloud contains many clusters of young bright stars seen as patches of light in binoculars. The LMC is about 160 000 light years away and the SMC 200 000 l.y away, both very close by for galaxies. (1 light year is about 10 000 billion, 10¹³ km.)
47 Tucanae, looks like a
faint fuzzy star on the edge of the SMC. It is a globular cluster, a ball of millions of stars.
A telescope is needed to see a peppering of stars around the edge of the cluster. Though it
appears on the edge of the SMC it is one-tenth the distance, 15 000 light years away, and is has
no connection to the Small Cloud. Globular clusters are mostly very old 10 billion years or
more; at least twice the age of the sun.
Omega Centauri, above and
left of the Pointers, is similar but larger than 47 Tucanae, around 17 000 light years away.
The Tarantula nebula is a
glowing gas cloud in the LMC. The gas glows in the ultra-violet light from a cluster of very hot
stars at centre of the nebula. The cloud is about 800 light years across. It is easily seen in
binoculars and can be seen by eye on moonless nights.
This nebula is one of the brightest known. If it was as close as the Orion nebula (in The Pot's handle) then it would be as bright as the full moon and look bigger than the whole constellation of Orion.
Canopus is the second brightest star. It is 14 000 times brighter than
the sun and 300 light years away. The planets Venus and Jupiter, and sometimes Mars, are
brighter
Alpha Centauri the brighter pointer, is the closest naked-eye star, 4.3 light-years away. Alpha Centauri is a binary star: two stars about the same size as the sun orbiting around each other in 80 years. A telescope that magnifies 50x shows the pair. (A very faint star, Proxima Centauri, orbits a quarter of a light-year, or 15 000 Sun-earth distances, from the Alpha pair.)
Coalsack nebula, is a cloud of dust and gas about 600 light years away, dimming the more distant stars in the Milky Way. Many similar 'dark nebulae' can be seen, appearing as slots and holes in the Milky Way. These clouds of dust and gas eventually coalesce into clusters of stars.
The Jewel Box is a compact cluster of young bright stars about 7000 light years away. The cluster formed less than 10 million ago. To the eye it looks like a faint star close by the second-brightest star in Crux. A telescope is needed to see it well.
Eta Carina nebula is a
glowing gas cloud about 8000 light years away.
The golden star in the cloud, visible in binoculars, is Eta [Greek η] Carinae. It is
estimated to be to be 60 times heavier than the sun and a million times brighter but is dimmed
by dust clouds around it. It is expected to explode as a supernova any time in the next few
thousand years.
Many star clusters are found in this part of the sky.
The Theta Carina cluster of stars is at one point of the 'Diamond
Cross'. It is also called the 'Five of Diamonds' cluster, the reason obvious when viewed in a
telescope. The cluster is about 500 light years away and is around 10 million years old.
NGC 2516 is right of the False Cross. To the eye it looks like a
faint comet. It is a nice sight in binoculars. The cluster is about 1200 light years away
Chart produced by Guide 8 software; www.projectpluto.com. Labels and text added by Alan Gilmore
The chart shows our northern sky in the evening The chart may need to be tilted to the left or right to match the sky, depending on the time of night. Interesting objects are described below.
Sirius and Mars are eye-catching objects in the northern sky in March. Sirius is high up in the sky, northwest of the zenith and white coloured. Mars is orange and low in the north at dusk. The most prominent northern constellations are on a diagonal line down and left of Sirius. First is Orion the Hunter marked by prominent Rigel and Betelgeuse with the well-known 'pot' or 'saucepan' pattern between them. Next is Taurus the Bull with Aldebaran being one of Taurus's eyes. The V-shaped Hyades cluster outlines the bull's head. (All these pictures were thought up by north hemisphere cultures so are upside down to us.) Further down the Pleiades or Matariki star cluster is close to the northwest skyline and sets early. Low in the north, left of Mars, are Castor and Pollux marking the heads of Gemini the Twins. Above and right of Mars is the Praesepe star cluster, a faint glow to the eye, making the shell of Cancer the Crab.
The Pleiades / Seven Sisters / Matariki / Subaru, (left) and many other
names, is a cluster of stars well known in both hemispheres. Though often called the Seven
Sisters, most modern eyes see only six stars. Dozens are visible in binoculars. The cluster is
about 400 light years away. Its brightest stars are around 200 times brighter than the sun.
It formed about 100 million years ago.
The Hyades cluster is 150 light years away. Its brightest stars (not
Aldebaran!) are about 70 times brighter than the sun. The cluster is about 700 million years
old. Aldebaran is not a member of the cluster but simply on the line
of sight. It is 65 l.y. away and 150 times brighter than the sun. Aldebaran is a giant star
about 25 times bigger than the sun though only five times heavier. Its orange colour is due to
its temperature, around 3500° C. The sun is 5500° C.
Orion, in the northern hemisphere view, has a shield raised toward
Taurus and a club ready for action. The line of three stars makes Orion's Belt. The line of
faint stars above the belt form Orion's Sword in the northern view, hanging from his belt.
To most southern hemisphere sky watchers the belt and sword form
The Pot or the Saucepan.
The Orion Nebula is visible in binoculars as a misty glow around the
middle stars of Orion's Sword or the handle of The Pot. It is a vast cloud of dust and gas about
1300 l.y. away and more than 20 l.y. across. Ultra-violet light from a massive, extremely hot
star in the cloud causes it to glow. Some stars in this region are around a million years old.
The sun, by contrast, is 4.6 billion years old. Stars continue to form in a giant cloud behind
the glowing nebula. There are many bright and dark nebulae in this region. The Horsehead
nebula, a favourite of astronomy books, is beside the right-hand star of Orion's Belt, but too
faint to be seen in small telescopes.
Sirius is the brightest star because it is both brighter than the sun
and relatively a close 8.6 l.y. away. Sirius was often called 'the dog star' being the
brightest star in Canis Major, one of the two dogs that follow Orion across the sky.
Rigel is a blue 'supergiant' star around 40 000 times brighter than
the sun and 800 l.y. away. Its surface temperature is around 20 000oC, giving it a bluish
colour. Betelgeuse is a red giant star 250 times bigger than the sun
-- wider than earth's orbit! -- but only around 20 times heavier. It is mostly very thin gas
surrounding a hot dense core. It is 10000 times brighter than the sun, about 400 l.y. away, and
has a surface temperature around 3000oC.
Mars, though bright, is disappointing in a telescope. It is more than 130 million km from us in March and shows only a tiny disc. It stays in the evening sky, getting fainter, for most of the year.