Eye on the Night Sky over Whitby

Comet Lovejoy - visible in the sky over Whitby
Comet Lovejoy - visible in the sky over Whitby

Planetary Skylights

Let us first have a look in the evening twilight sky where brilliant Venus (you cannot mistake it low down above the SW horizon) is involved in a close encounter with Mars on February 21.

The pair will be less than a degree apart, certainly within the same binocular field. The amber hue of Mars will reside to the upper right of Venus appearing much less bright. View around 6.30pm.

A slim crescent moon joins the party on the 20th and 21st. Venus may be conspicuous during the early part of the evening.

Jupiter, however rules the night sky. It offers up a wealth of detail when viewed through a scope, the dance of the galilean moons from day to day being particularly fascinating to follow.

Saturn is visible in the dawn sky; look for it after 5am when it lies low to the ESE a hand span above the horizon. By 6.30pm it lies almost due south and above the orange hue of Antares, chief star in Scorpius.

The moon lies nearby on the 13th.

The weather wasn’t particularly kind over the January ‘dark window’ period, throughout which comet Lovejoy was readily visible when conditions relented.

Cloud, winds, frost, mist, all took turns in making observations of the comet a little tricky and very frustrating.

Despite these difficulties, the comet was spotted by quite a number of people and was easily seen through binoculars as a small ghostly grey blob.

By late January there was even a hint of a tail visible. The comet is now fading slowly and with moonlight interfering for the first week in February it will have moved high into the NW sky before we have another ‘dark window’ period in which to view. Lovejoy should still be apparent in binoculars or a scope

however, so there is still time to spot this green headed visitor before it finally fades, not returning for another 8,000 years.

Given a clear and dark sky, February is a great time to become acquainted with the winter celestial night sky, the southern aspect is especially studded with bright stellar jewels.

Of these no other star catches the eye more than sparkling Sirius - the ‘Dog star’, which arcs low above the southern horizon.

Sirius is the brightest star in the entire night sky and lies in Canis Major - the Great Dog, a constellation that from the UK only just clears the horizon.

Because of its brilliance, coupled with its altitude, Sirius often appears to twinkle vigorously (scintillation), much more so than other stars.

This scintillation can be a cause of some consternation and on a number of occasions I have been contacted by individuals seeking advice on “the flashing object” visible low to the south. Certainly when viewed through binoculars or a telescope, Sirius is a mesmerizing spectacle of ever-changing sparkling hues.

Throughout human history Sirius, meaning, “sparkling or scorching one” has been the most brilliant of the fixed stars and as such revered in many cultures. In ancient Egypt around 3000 BC, Sirius was the “Nile star” whose appearance just before dawn near the summer solstice heralded the impending rise of the Nile into flood, an event upon which Egyptian agriculture and therefore civilization depended.

This “helical” or first rising is referred to in numerous temple incriptions such as those at Kamak and Denderah which were orientated to the rise of Sirius.

In the ancient Greek and Roman world, the rising of Sirius was regarded as unfortunate, its searing light thought to add to the scorching heat of July and August and attributed to bringing forth fever and madness during the so called “dog days of summer”.

Several legends are attached to these groups. One Greek myth associates Canis Major with Laelaps, who in a race outran the fastest creature in the world (supposedly a fox) for this reason Zeus, placed him in the sky. Another myth has both the dogs assisting Orion whilst he was out hunting. The greater dog is pursuing Lepus- the Hare, visible in the sky crouching below the feet of Orion.

The lesser dog is stranded on the other side of a river, the Milky Way. Yet another tale has the two dogs sitting under the table at which the twins of Gemini (Castor and Pollux) are dining.

The faint stars between Canis Major and Gemini are the crumbs the twins have been feeding to the animals.

Although Sirius is twice the size and over twenty five times more powerful than our Sun, its in our night sky is really down to its proximity, a mere 8.6 light years, making it the fifth nearest star.

It is believed to be a member of the Ursa Major stream, a moving cluster of stars that also contains five of the Plough’s stars. The Great Dog is accompanied across the sky by the lesser dog - Canis Minor, which lies at shoulder height to Orion and some way above Sirius.

The eighth brightest star in the sky, Procyon - which means “before the dog”, distinguishes the lesser dog.

It is also situated nearby at just over 11 light years. Careful observation of this region of the sky from a dark location will reveal the winter Milky Way flowing between the two dogs.

Both Sirius and Procyon have White Dwarf companion stars, the degenerate core of less massive, Sun-like stars.

White Dwarfs have incredibly high densities and extremely small diameters, 20,000 miles in the case of the ‘Pup’, Sirius’s companion. Just a teaspoon of

‘Pup’ material would weigh as much as a ten bull elephants!

It is a pity that both the Pup and Procyon’s companion are overwhelmed by the radiance of their larger neighbours and only visible in larger scopes.

So on a clear night during February, take a look at the brightest star in the night sky – but please don’t go barking mad.