The Solar System in February 2015
All dates and times are NZDT (UT +13 hours) unless otherwise specified. 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 February 28 morning evening morning evening rise: 6.23am, set: 8.44pm rise: 6.57am, set: 8.08pm Twilights Civil: starts: 5.55am, ends: 9.13pm starts: 6.31am, ends: 8.35pm Nautical: starts: 5.17am, ends: 9.51pm starts: 5.57am, ends: 9.09pm Astro: starts: 4.35am, ends:10.32pm starts: 5.22am, ends: 9.44pm
February Phases of the Moon (times as shown by guide)
Full moon: February 4 at 12.09 pm (Feb 3, 23:09 UT) Last quarter: February 12 at 4.50 pm ( 03:50 UT) New moon: February 19 at 12.47 pm (Feb 18, 23:47 UT) First quarter: February 26 at 6.14 am (Feb 25, 17:14 UT)
The Planets in February
Venus and Mars are close together and visible for a short time after sunset. Jupiter reaches opposition and is visible most of the night but Saturn is only visible in the morning sky although it rises just before midnight by the end of February. Mercury moves rapidly up into the morning sky to become easily visible an hour before sunrise in the second half of the month.
MERCURY was at inferior conjunction with the Sun on January 30 so it starts February much too close to the Sun to observe. It subsequently moves rapidly into the morning sky, rising 45 minutes before the Sun on the 6th and nearly 100 minutes earlier a week later. On the 13th at 5.40 am, an hour before sunrise, Mercury at magnitude 0.6 will be some 7° above the horizon, easily the brightest low object a little to the south of west.
From the 17th and on into early March, Mercury will rise more than 2 hours before the Sun and it will the planet will gradually brighten a little. On the 28th Mercury will be more than 12° above the horizon an hour before sunrise, making it an easy morning object with a magnitude 0.1. This will be the best morning appearance of Mercury for the year for the southern hemisphere.
VENUS and MARS become a pair of early evening planets during February. On the 1st, Venus is 9.5° left of Mars. Both planets start February in Aquarius. Both move into Pisces during the month with Venus closing in on Mars. On the 22nd, they are at their closest with Venus less than half a degree above Mars. Their brightness contrast will be extreme, Venus more than 100 times brighter than Mars.
The previous evening, when the two planets will be only slightly further apart, the moon as a fine crescent will be 4.5° to their right. By February 28 Venus will be nearly 3° ahead of Mars.
The two planets set a little over an hour after the Sun throughout February. On the 1st Mars almost 90 minutes later, Venus 68 minutes later. On the 28th Mars will set first, 63 minutes after the Sun, while Venus sets 8 minutes later (as seen from Wellington).
JUPITER is at opposition on February 7. Thus it will be visible most of the night, although low to the northeast early evening, particularly at the beginning of the month. At opposition, Jupiter will be 650 million km, 4.35 AU, from the Earth and 5.33 AU from the Sun.
The planet starts February in Leo. During February it moves to the west (that is in a retrograde sense) and into Cancer on the 4th. Early that evening the full moon will be some 4.5° to the upper right of the planet. By midnight the sky will have rotated to bring the moon almost directly above Jupiter, its distance increasing to 5°.
Mutual Events of Jovian Satellites
There are about 16 mutual events of Jupiter's Galilean satellites observable from NZ during February. The events involve either occultations or eclipses of one satellite by another. Visually, mutual occultations are the more interesting to watch as satellites can be seen to merge and separate over a period several minutes. Eclipses are normally partial events with fairly small magnitude changes of the eclipsed satellite. Consequently they are mostly difficult to detect visually. Total eclipses are rare.
Useful observations and timings of both types of event can be made by those set up for the video observation of minor planet occultations.
For more details refer to the IMCCE web site, <http://www.imcce.fr/phemu/> where predictions and requirements for observing and reporting information are available. Users of Dave Herald's Occult program can generate their own predictions.
SATURN remains a morning object throughout February. On the 1st it rises close to 1.30 am, by the end of the month a few minutes before midnight. The planet will be in Scorpius near the close double star beta Sco, magnitude 2.6. Saturn will be about 9° from Antares.
On the morning of the 13th, the moon, just past last quarter, will be 4.5° to the left of Saturn as seen in the early dawn sky.
During February Saturn's north pole is tilted almost 25° towards the Earth. This brings the northern surface of the rings well into view. They should be visible in binoculars, although a small telescope is likely to give a better view.
URANUS remains in Pisces as an evening object magnitude 5.9. By the end of February it will set at 8.30pm, so less than 90 minutes after the Sun and low in the fading twilight.
NEPTUNE is within a degree of Venus on the 1st so will be low in the twilit sky. Despite being close to Venus, Neptune, magnitude 8.0, is likely to be difficult to see in binoculars due to twilight. Neptune is at conjunction with the Sun on the 26th. It will then be 4.63 billion km, almost 31 AU, from the Earth and 30 AU beyond the Sun.
PLUTO is in Sagittarius and rises more than 4 hours before the Sun by the 28th. Its magnitude is 14.4
(1) Ceres is a morning object in Sagittarius with magnitude 9.2. By the end of the month it will rise over 4 hours before the Sun.
(3) Juno starts February in Hydra. It moves into Cancer on the 16th. This places it in the evening sky, although it doesn't set until several hours after midnight. Its brightness fades during the month from magnitude 8.2 to 8.9
(4) Vesta moves further into the morning sky following conjunction. It rises less than an hour before the Sun on the 1st, two hours before it on the 28th. The asteroid is in Capricornus, at magnitude 8.
(7) Iris and (8) Flora are both in Leo, but at opposite sides of the constellation, nearly 30° apart. Iris's magnitude varies from 9.5 to 9.0, Flora's at its brightest is 9.1 when at opposition on the 17th. Iris doesn't reach opposition until early March.
The follwing table lists various solar system object events during February. A list of astronomical terms used in may be found after the table.
|February 1||Venus 0.8 degrees south of Neptune|
|February 3||Moon full|
|February 4||Jupiter 5.0 degrees north of the Moon|
|February 5||Regulus 3.8 degrees north of the Moon|
|February 6||Moon at apogee
Jupiter at opposition
|February 9||Spica 3.2 degrees south of the Moon|
|February 11||Mercury stationary|
|February 12||Moon last quarter|
|February 13||Saturn 2.1 degrees south of the Moon|
|February 14||Moon southern most declination (-18.4 degrees)|
|February 15||Pluto 3.0 degrees south of the Moon|
|February 17||Mercury 3.4 degrees south of the Moon|
|February 18||Moon new|
|February 19||Moon at perigee
Neptune 3.6 degrees south of the Moon
|February 20||Venus 2.0 degrees south of the Moon|
|February 21||Mars 1.5 degrees south of the Moon
Uranus 0.3 degrees south of the Moon Occn
|February 22||Venus 0.4 degrees south of Mars|
|February 24||Mercury greatest elong W(27)|
|February 25||Moon first quarter
Aldebaran 1.0 degrees south of the Moon Occn
|February 26||Neptune at conjunction|
|February 27||Moon northern most declination (18.3 degrees)|
- apogee: Furtherest point in the orbit of a body orbiting the Earth
- conjunction: Two astronomical objects are 'lined up' (have the same right ascension) when viewed from Earth. If only one object is mentioned the Sun is generally the other object.
- declination: 'Latitude' for celestial objects. The distance in degress above (north) or below (south) the celestial equator.
- perigee: Nearest point in the orbit of a body orbiting the Earth