The night sky in February 2018

posted 31 Jan 2018, 15:01 by Pete Collins   [ updated 1 Feb 2018, 07:41 ]
by Anne Holt

Sunrise:   1st    07.54         28th    06.59
Sunset:    1st    16.51         28th    17.44

Astronomical darkness: 
1st:   18.52  -  05.51         28th:  19.40  -  05.01

Highlights

Not much to highlight this month.  Jupiter is shining brightly in the morning sky and, towards month end, Venus re-appears as an evening 'star'.

The Sun is rising a couple of minutes earlier and setting a couple of minutes later each day now, but we still have quite a long period of astronomical darkness - 11 hours on 1st and a little over 9 hours on 28th.  However, by month end, astronomical twilight doesn't end until 19.40 - almost half way through our meeting time.

On 15th there is a partial Solar eclipse, but it's only visible much further South - in parts of S America, the Southern Pacific & Atlantic oceans and Antarctica.

There are some bright early evening passes of the ISS in the first half of the month. See www.heavens-above.com for details.

One of the most interesting things this month is something that doesn't happen.  We have what is referred to as a Black Moon, meaning a calendar month with no full Moon.  This can only happen in February and is quite rare,  the last time was in 1999 and the next won't be until 2037.  Black Moon isn't a recognised astronomical term and is also used to describe the second new Moon in a month or the third new Moon in a season with 4.  Both of these seem to make more sense, referring to something which does happen, rather than something which doesn't.

Constellations

Orion
and Taurus are now above the horizon as the sky darkens but start to set at around 2am at the start of February and soon after midnight by the end of the month. Gemini and Auriga are still prominent, remaining above the horizon until the early hours. Leo, the signpost constellation of Spring, is now high in the sky for most of the night and Bootes, with it's bright red star Arcturus is rising soon after 11, and around 9 at month end. In the early part of the evening the Plough is low in the North East standing on its 'handle', and Cassiopeia high in the North West as darkness falls. By month end, the Summer Triangle will have risen soon after 3am - Summer already?  Someone better tell the weather.

Planets

Mercury:  in Capricorn, mag -0.6. At the start of February it rises only 14 minutes before the Sun and won't be visible in the bright pre dawn sky.  On 17th it moves into Aquarius on the same day as it reaches superior conjunction, the furthest point in its orbit from Earth, on the opposite side of the Sun.  It then becomes an evening object but still not easily seen.  By the end of Feb it sets at 18.27,  only 45 minutes after the Sun, and will have brightened to mag -1.4.

Venus:  in Capricorn,  mag -3.9. An evening object.  At the start of February it sets only 18 minutes after the Sun, so won't be visible despite its brightness.  It moves into Aquarius on 9th and by mid month might be seen very low in the West, soon after Sunset.  On 28th it sets at 18.42, almost an hour after the Sun, and will appear very close to the ten times fainter Mercury.

Mars:  in Scorpio, mag 1.2. A morning object, rising soon after 3am throughout February.  On 1st this is about 3 and a half hours before sunrise.  On 9th it moves into Ophiuchus.  It spends most of February quite close to the 'rival of Mars', red supergiant Antares, at their closest - about 5 degrees apart - on the morning of 12th.  because Mars is still relatively distant from Earth, it is still quite faint and will appear similar in brightness to the star, as well as in colour.   At around 4.30 on the morning of 9th, the 35% lit Moon joins them to form a straight line. 

Jupiter;  in Libra, mag -2.0. Shining brightly in the morning sky.  On 1st it rises at 02.12 and culminates at 06.39, just as the sky begins to brighten.  By month end it will be slightly brighter at mag -2.2, rising just an hour after midnight and culminating while the sky is still at its darkest.

Saturn:  in Sagittarius, mag 0.6. Rises a couple of hours before the Sun at the start of February, but is very low in the SE brightening sky.  On the morning of 11th the 18% lit Moon will be just 4 degrees NW of the planet.  By the end of the month it rises at 04.25, 2 and a half hours before the Sun, while the sky is still dark.  It will still be very low - only about 8 degrees - and difficult to see.

Uranus:  in Pisces, mag 5.8. The only planet which is currently in the northern celestial hemisphere is now past its best for observing.  On 1st it sets just before midnight, having reached its highest point in the sky as the Sun sets.  By the end of the month it will have faded slightly to mag 5.9 and be setting a few minutes after 10pm.

Neptune:  in Aquarius, mag 8.0. At the start of February it sets only 2 hours after the Sun and, by month end, at 18.00 - only 16 minutes after Sunset, so not visible.

Dwarf Planets  

Ceres, in Cancer, is still very well placed for amateur observation, especially in the early part of Feb, when it is just past opposition and is at mag 6.9.  On 1st it culminates at 00.41, by month end it reaches its highest point at 22.23 and will have faded to mag 7.3.  Because it is so small, it will only ever show as a point of light in amateur scopes so is probably best as a photographic target.
Eris in Cetus,  Haumea in Bootes and Makemake in Coma Berenices are all well placed this month, but at magnitudes of around 17 to 18 are out of range of amateur scopes.
If you really want to try imaging them, exact positions can be found on
This site also gives positions of major planets, asteroids etc.

Meteor Showers

Unless you happen to be in the southern hemisphere, when the alpha Centaurids can be seen between Jan 31st and  Feb 20th,  this month is very poor for meteors.  
Some sites mention the delta Leonids,  active Feb 5th to March 19th, peak 22nd, ZHR 3.    These are said not to be associated with any particular comet but to be caused when the Earth passes through a dust cloud across its orbit.
However, the International Meteor Organisation no longer includes this in their listings, so maybe it was more temporary than first thought.

Comets

There are still several faint comets around but none brighter than mag 10.5.  If you do want to try your luck photographing one of these, details can be found on
The next reasonably bright comet expected in our skies is 46P/Wirtanen, which is predicted to reach mag 3 in December.
But we all know what comets are like, so don't hold your breath!
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