the solar system in February 2016

Dates and times shown are NZDT (UT + 13 Hours) unless otherwise stated. Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

Sunrise, sunset and twilight times in February

                            February  1  NZDT                February 29  NZDT
                    morning  evening                 morning  evening
       SUN: rise:   6.23am,  set:  8.44pm    rise:   6.58am,  set:  8.07pm
  Civil:    starts: 5.55am,  ends: 9.13pm    starts: 6.32am,  ends: 8.34pm
  Nautical: starts: 5.17am,  ends: 9.51pm    starts: 5.58am,  ends: 9.07pm 
  Astro:    starts: 4.34am,  ends:10.33pm    starts: 5.23am,  ends: 9.43pm

February PHASES OF THE MOON (times as shown by GUIDE)

          Last quarter:  February  1 at  4.28 pm (03:28 UT)
  New moon:      February  9 at  3.39 am (Feb  8, 14:39 UT)
  First quarter: February 15 at  8.47 pm (07:47 UT) 
  Full moon:     February 23 at  7.20 am (Feb 22, 18:20 UT)

The planets in February

Jupiter will be in the sky from soon after sunset by the end of February. The other planets remain objects of the morning sky. Venus and Mercury are a close pair in the dawn sky and will be an interesting to watch as their distance apart vary during the month. The asteroid (5) Astraea is at a particularly good opposition mid February.

Mercury and VENUS form a pair of planets rather low in the dawn sky throughout February. At the beginning of the month both planets will be in Sagittarius. During February they move into Capricornus, Mercury on the 14th and Venus 3 mornings later.

On the morning of the 1st, Mercury rises almost 2 hours before the Sun, with Venus rising some 35 minutes earlier. Mercury will be half a degree below the 2.9 magnitude star pi Sgr, with Venus some 7 degrees above Mercury.

During the first half of February Venus will close in on Mercury until the two are some 4 degrees apart mid month. After that as Mercury's rate of motion increases it will draw further ahead of Venus until the two are again 7 degrees apart by the end of the month. Mercury will remain a few degrees below Venus and a little to its right all month.

Mercury's magnitude brightens from 0.1 to -0.3 during February. It reaches its greatest elongation, 26 degrees west of the Sun on the 7th. By the end of February Mercury rises some 95 minutes before the Sun, with Venus rising half an hour earlier. An hour before sunrise, Mercury will be only 6 degrees above the horizon

Mars rises half an hour after midnight on the 1st advancing to 11:45 pm by the 29th. The planet is in Libra, near the wide binary star alpha Lib at the beginning of the month. The two are closest on the 2nd when Mars, magnitude 0.8, will be a degree below the pair, with the 45% lit moon 4.5 degrees lower than Mars. For the rest of the month Mars makes its way eastwards through Libra but doesn't pass close to any bright stars.

At midnight on the 29th February the moon will again be near Mars, some 5.5 degrees from the planet which will have brightened to magnitude 0.3. A few hours later, on the morning of March 1, the two will be 4 degrees apart

Jupiter is in Leo during February. On the 1st it rises about 10.20 pm, by the end of February it will rise almost 2 hours earlier, some 15 minutes after the Sun sets, so the planet should be readily visible by mid evening.

In the late evening of February 24, the almost full moon will be 4 degrees to the left of Jupiter; their separation increases to 6.5 degrees a little before sunrise the following morning when Jupiter will appear below the moon.

Saturn rises shortly after 2 am on the 1st and 20 minutes after midnight on the 29th. So it is still a morning object. The planet is in Ophiuchus about 8 degrees below Antares, as seen in the morning sky. At magnitude 0.5, Saturn is a little brighter than the star.

On the morning of February 4, the 26% lit moon will be 4 degrees to the lower left of Saturn

Outer planets

Uranus remains in Pisces during February at magnitude 5.9. It is an evening object setting just before 11.30 pm on the 1st and just after 8.30 pm, 90 minutes after the Sun, on the 29th.

Neptune, in Aquarius, sets about 70 minutes after the Sun on February 1. It is at conjunction with the Sun on the 29th. At conjunction Neptune will be half a degree south of the Sun as seen from Earth. The planet will then be 4.63 billion km, 30.95 AU, from Earth and 29.95 AU beyond the Sun.

Pluto continues to be in Sagittarius throughout February at magnitude 14.4. It is close to Mercury at the beginning of the month, the two separated by just over half a degree on the 1st. Five nights later Venus will be just over 1 degree from Pluto. These close approached will occur close to the star pi Sgr, magnitude 2.9. Pluto is less than 6 arc-minutes from the star on the 14th. At magnitude 14.4 a moderate telescope is needed to see, or image, the dwarf planet. Low altitude and dawn twilight will make this very difficult.

A better chance of finding Pluto close by pi Sgr will occur in June when Pluto's retrograde motion takes it less than 3 arc minutes from the star.

BRIGHTER ASTEROIDS: (1) Ceres is in Aquarius during February but getting close to the Sun. By the 29th the two will be only 8 degrees apart.

(4) Vesta, magnitude 8.3, starts February in Cetus. On the 1st, Vesta will set just before midnight. Early in the month the asteroid is just over 5 degrees from Uranus. On the 12th Vesta joins Uranus in Pisces but their distance apart will gradually increase. By February 29 Vesta will set about 10.20 pm.

(5) Astraea. This 125 km diameter asteroid is in Leo and starts February at magnitude 9.3. On the 1st it will rise at 9.19 pm at Wellington. The asteroid will then be just over half a degree above Regulus, mag 1.4, with no other star as bright as Astraea between the two. This will make finding Astraea fairly easy in the late evening.

Astraea is at opposition mid February with a magnitude 8.7. By then it will be some 3 degrees left of Regulus as seen late evening. At opposition it will be 2.086 AU from the Sun, very close to its perihelion, and 1.1 AU from Earth. The relatively close approach makes this a particularly favourable opposition for observation.

By the end of February, Astraea will be back to magnitude 9.3

Brian Loader  
New Zealand