Stargazing: What to look out for in February's sky

February began with National Astronomy Week, running from the 1st through to the 9th.  

This is timed to coincide with a particular event visible during the current alignment of most of the major planets in the sky at once. 

Despite the media hype about this occurring on one night last month, the planets have been on view like this since December and will continue to be visible together into March. Hollywood representations of planetary alignments show each of the planets, in order, and in an arrow-straight line leading away from the Earth.  This is NOT what is meant by alignment and is not what will be seen. This is also the common misconception of an alignment.

In astronomical terms, an alignment is when multiple planets are visible in the same section of the sky. The apparent (not real) line is across the sky, from horizon to horizon, as in the current case.  The rarity is that all of the major planets are on view at the same time in a single  night.

If one looks towards the South, the first thing that one would notice, as son as it is dark, is brilliant Venus in the South-West. Below and slightly to the right of Venus is another bright dot. This is Saturn, leading the procession even though it is the sixth most distant planet from the Sun. Venus is second in the procession even though she lies in the opposite direction (between Earth and the Sun) in her orbit.  The whole spectacle is merely a line of sight effect caused by our perception of a 3D solar system onto an, effectively, 2D black background. 

Following the line from Saturn to Venus and on up through South, another bright object high in the sky is Jupiter and is visible all night. Jupiter lies just to the left of the faint group of stars called the Pleiades, in Taurus. Further East, lying between stars of the Twins, Castor and Pollux, is Mars which is actually closer to Earth than Jupiter. These are all of the planets easily visible to the naked eye.

In fact, for those with telescopes, Neptune is also part of this procession of planets, lying just below Venus in the sky, placing it third in the line even though it is the most distant of the major planets.  Even Uranus is visible to those with good binoculars or telescopes lying to the right, and slightly below, the Pleiades at about the same distance from the cluster as Jupiter.

Furthermore, by the beginning of March, Mercury joins the line-up between Saturn and Venus.

Throughout the month the Moon will also be seen to travel along this line, passing each of the planets in turn. This is because the apparent paths of the Moon and planets all follow a line known as the Ecliptic.

The specific event that NAW is set to mark is the passing of the Moon and Mars.  Because the Moon is much closer than Mars, from some parts of the country, the red planet will be obscured from our view for a time. This is known as an “occultation”. It will, at least, be a very close pass from our latitudes and observers with telescopes may be rewarded with views of Mars “rolling along”  on the edge of the Moon.

Skynotes

Please note: all times given in this article are in GMT.

Sun: At the start of the month there are just 9 hours of daylight but as February progresses the length of day will increase to almost 11 hours.

Mercury:  Mercury is not easily visible this month..

Venus:  Venus is a  bright object in the early evening sky, fairly low in the South-West as soon as it gets dark. The planet will reach its maximum brightness of minus 4.5 (the lower the number, the brighter the object) on the 16th . Venus is seen against the background stars of Pisces.

Mars:  Mars is visible all night long as a bright red object in Gemini. Mars will be passed extremely closely by the Moon on 9th (see main article).

Jupiter:  Jupiter is visible all night long and is seen high in the South, amongst the stars of Taurus.. The giant planet is seen against the background stars of the Hyades and close to the Pleiades star clusters either of which would make a good photo opportunity. 

On the 4th Jupiter will end its apparent “backwards” (retrograde) motion and resume its more normal Eastward (prograde) motion. This is caused by the Earth “catching up” with Jupiter on the inside track, as it were, of its orbit.

Saturn: Saturn starts the month low in the Western evening sky, and sets just a couple of hours after darkness falls.

Uranus and Neptune: Uranus is seen against the background stars of Taurus and close to the Pleiades star cluster.  It is visible, although small and difficult to find, throughout most of the month. 

At magnitude 5.8 it is visible in binoculars.  Look for a tiny greenish disc compared to the pinpoints which are the stars.  Neptune is much lower in the sky, in the constellation of Pisces and is becoming increasingly difficult to spot. At magnitude 7.8 it will require large binoculars or a small telescope to find it.  Neptune displays a smaller and truly blue disc compared to that of Uranus although it will appear only as a bluish star to most small instruments. 

Meteor shower:  There are no regular meteor showers this month. However stray or sporadic meteors can still be seen at any time. Some of these can be very bright.

The First Quarter Moon occured on February 5th with Full Moon on the 12th. Last Quarter then follows on 20th February and Newl Moon on 28th.  

Data supplied by Dale Giles, Torbay Astronomical Society 

Diary dates

The next meetings of the Torbay Astronomical Society will be held at Torquay Boys Grammar School, Shiphay Manor Drive, TQ2 7EL.   

On February 13th, TAS member, Maxwell Maltz will present a talk about his University studies on “Computer Simulations in Astronomy”. This meeting to be held in the Forum Lecture Theatre.  

Then on February 27th  the society will hold its regular monthly observing evening in room PL4 and the observatory (weather permitting) when members will, once again, be delighted to provide views of the objects discussed in this article. 

For details contact the Secretary TAS on astrosecretary@gmail.com. Visitors and prospective members especially welcome.