What beginning stargazers need to see and learn from the night sky

If you are new to the stargazing hobby, you are likely still in the process of “learning” the sky, and how to find your way around. While there are many ways of learning to find objects to view, one of the easiest is to learn to identify the constellations. Many constellations contain spectacular deep sky objects within their borders, so if you know where a particular constellation is at any given time, you can drastically reduce the time you spent looking for an object.

That said though, many constellations look nothing like the mythological creatures they are said to represent, and even some professional astronomers have some difficulty in identifying some of the more obscure constellations. Moreover, not all constellations are always visible from any spot on the globe, but observers in the UK are fortunate in that the five biggest constellations out of the 88 recognized constellations are all visible from within the borders of the United Kingdom. Let us look at each of these constellations in a little more detail.

Hydra, the Water Snake

This image shows Hydra relative to some other major constellations.

Image credit: www.space.com
Image credit: Space.com

Hydra is the largest of all the constellations, and it takes up 3.15% of the sky, which works out to 1 303 square degrees between latitudes +54° and -83° in the southern sky. Although the constellation is located in the southern sky, it is fully visible from the UK along with some others that also fall in the southern sky. The best time to see the Water Snake stretched out over its full length (102.5 degrees) is at around 9 PM (Local Time) during April.

All told, Hydra has 238 stars, of which Alphard (Alpha Hydrae) is the most luminous with an apparent visual magnitude of 1.98. The constellation’s star count includes 18 stars that host 23 planets between them. Notable deep sky objects in Hydra include the open cluster Messier 48, the globular cluster M68, the Southern Pinwheel Galaxy (M83), the Hydra Cluster of galaxies, Tombaugh’s Globular Cluster (NGC 5694), the Ghost of Jupiter nebula, and the spiral galaxy ESO 510-G13.

Hydra is bordered by the constellations Antlia, Cancer, Canis Minor, Centaurus, Corvus, Crater, Leo, Libra, Lupus, Monoceros, Puppis, Pyxis, Sextans and Virgo, which it makes it easy to identify, since some of the bordering constellations are very prominent.

Virgo, the Virgin

The image shows Virgo relative to other major constellations.

Image credit: Space.com
Image credit: Space.com

Virgo is one of the 12 zodiac constellations first catalogued by the Greek astronomer Ptolemy in the 2nd century. Occupying an area of 1 294 square degrees, between latitudes +80° and -80° in the southern hemisphere, it is the second largest of all the constellations. Like Hydra, Virgo is visible from the UK because it lies close to the ecliptic. The best time to view Virgo is at about 9 PM (Local Time) during May.

Virgo contains the autumn equinox point, a point in the sky that marks the intersection of the ecliptic and the celestial equator. The opposite point is in the constellation Pisces; the two points mark the beginning of the northern autumn, and the southern spring respectively when the Sun crosses these positions.

Notable deep sky objects in Virgo include the very bright galaxies M49, M58, M59, M60, M87, as well as the famous Sombrero Galaxy, M104. Virgo also has 26 stars that host 33 planets between them, more than any other constellation. Constellations that border on Virgo are Boötes, Coma Berenices, Corvus, Crater, Hydra, Leo, Libra and Serpens Caput.

Ursa Major, the Big Bear

The image shows Ursa Major relative to other major constellations.

Image credit: IAU/Sky & Telescope
Image credit: IAU

Ursa Major is the largest of the northern constellations, and the third largest overall, taking up an area of 1 280 square degrees between latitudes +90° and -30° in the northern sky. The Bear is perhaps best known for the famous Plough, or Big Dipper asterism (as it is known in the USA), it contains. Along with the constellations Orion and the Southern Cross, Ursa Major has a history dating back several thousand years, and it has been known in every major culture of the world, albeit under different names at different times. Ursa Major is best seen at about 9 PM (Local Time) during April.

All told, Ursa Major has 209 stars of which 18 host 24 planets between them. Apart from lots of planets, Ursa major also contains some spectacular deep sky objects, some of which are easy targets for amateur equipment. Some notable objects include the Pinwheel Galaxy (M101), Bode’s Galaxy, the Cigar Galaxy, and the Owl Nebula.

Constellations bordering on Ursa Major are Boötes, Camelopardalis, Canes Venatici, Coma Berenices, Draco, Leo, Leo Minor and Lynx.

Cetus, the Whale

The image shows Cetus relative to some neighbouring constellations. Note the location of the star Mira in the centre of the constellation; Mira is the prototype for the Mira class of variable stars.

Image credit: IAU
Image credit: IAU

Cetus is located in a region of the sky known as “Water”, along with some other constellations whose names are connected to water in some way. The constellation takes up an area of 1 231 square degrees between latitudes +70° and -90° of the southern sky. The Whale is best seen at about 9 PM (Local Time) during November.

All told, the constellation contains 189 stars, 21 of which host 27 planets between them. Apart for stars like Deneb Kaitos (Beta Ceti), Menkar (Alpha Ceti), and Mira (Omicron Ceti) that are all famous for various reasons, the constellation also includes some notable deep sky objects, such as M77, a barred spiral galaxy located about 50 million light years away, and the “Pac-Man Nebula” that is named for the arcade game character, because it appears to be slurping up the stars in the surrounding star field.

Constellations that border on Cetus are Aquarius, Aries, Eridanus, Fornax, Pisces, Sculptor, and Taurus.

Hercules, the (Roman) Hero

The image shows Hercules relative to other major constellations.

Image credit: IAU
Image credit: IAU

Although Hercules was catalogued by the Greek astronomer Ptolemy in the 2nd century, it’s history dates back to ancient Sumerian times, when it was associated with the hero Gilgamesh in an epic tale that resembles some stories from the Old Testament.

Being the fifth largest constellation in the sky, Hercules takes up an area of 1 225 square degrees between latitudes +90° and -50° in the northern sky. All told, the constellation contains 245 stars, 16 of which host 19 planets between them. However, despite the constellations’ large star count, it does not contain any first magnitude stars, but the constellation is relatively easy find. Look for the prominent Keystone asterism that is made up of Pi, Eta, Zeta, and Epsilon Herculis, the four brightest stars in the constellation.

Some notable deep sky objects in Hercules include M13, a large globular star cluster located on one side of the Keystone, M92, which at about 14 billion years old is arguably the oldest star cluster known, the Hercules Cluster of galaxies (NGC 6210), and Abell 2199, a large galaxy cluster. Particularly noteworthy is the fact that Hercules contains the Hercules–Corona Borealis Great Wall, the largest known superstructure in the Universe. This conglomeration of galaxy clusters stretches over 10 billion light years in length, 7.2 billion light years in breadth, and 1 billion light years in depth.

Conclusions

So there you have it. The 5 largest constellations visible from the UK. Hopefully as a newbie to stargazing, you’ll find this useful in your quest to learn about what’s up there in the night sky to see and enjoy. Whether you’re a seasoned observer or starting out from scratch, there’s always new and fascinating heavenly bodies to find and observe so have fun and enjoy your experience. And remember, the best way to see the night sky is to purchase one of the best beginners telescopes on the market. Buying the right one should last you many years to come and be a solid investment.