The Solar System In February 2017

Dates and times shown are NZDT (UT + 13 hours).

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 31  NZDT
                    morning  evening                 morning  evening
       SUN: rise:   6.24am,  set:  8.43pm    rise:   6.58am,  set:  8.07pm
Twilights
  Civil:    starts: 5.56am,  ends: 9.12pm    starts: 6.32am,  ends: 8.34pm
  Nautical: starts: 5.18am,  ends: 9.50pm    starts: 5.58am,  ends: 9.08pm
  Astro:    starts: 4.36am,  ends:10.32pm    starts: 5.23am,  ends: 9.43pm

February phases of the moon (times as shown by guide)

          First quarter: February  4 at  5.19 pm (04:19 UT)
  Full moon:     February 11 at  1.33 pm (00:33 UT)
  Last quarter   February 19 at  8.33 am (Feb 18, 19:33 UT)
  New moon:      February 27 at  3.59 am (Feb 26, 14:59 UT)

Eclipses

Neither the penumbral eclipse of the Moon on February 11 nor the annular eclipse of the Sun on the 26th, are visible from New Zealand. Further details of both eclipses can be found on the RASNZ web page, <www.rasnz.org.nz/in-the-sky/eclipses>.

The planets in February 2017

Venus remains the obvious bright planet in the evening sky but gets considerably lower, setting earlier, during the month. Mars, much fainter, is only a few degrees higher. Jupiter begins to move into the late evening sky; in the morning sky it will be joined by Saturn and, during the first part of the month, by Mercury.

Evening planets, venus and mars

Venus will remain brilliant in the evening sky throughout February reaching magnitude -4.8 by the 28th. It will get much lower in the western sky during the month, setting before 9 pm, about 45 minutes after the Sun, at the end of February. The planet is in Pisces all month.

Mars will be about 5.5° above and to the right of Venus on the 1st, with the crescent moon less than 3° away on the other side of Mars. With a magnitude 1.1, while still quite bright, Mars will have less than 1% of the brilliance of Venus.

For the first few days of February the relative positions of two planets will change little, both moving to the east through the stars. Later in the month, as Venus' apparent motion slows, Mars will draw away from it. Venus is stationary early in March

Towards the end of February, Mars will pass Uranus. The two are closest on the evening of the 27th, when Uranus will be just over half a degree to the upper left of Mars. With a magnitude 5.9, Uranus will be an easy binocular object, with no star of a similar magnitude close by.

By the end of February Mars will set about 100 minutes after the Sun and nearly an hour later than Venus.

Late evening and morning

Jupiter rises near 11.30 pm on the 1st and 9.40 on the 28th. So by then it will be an obvious late evening object to the east. Anyone who has seen Jupiter in the morning sky recently will know that it is close to the first magnitude star Spica. Early in the month their separation will be 3.6°. On the 6th Jupiter is stationary, after that date it will start moving slowly to the west as the faster moving Earth begins to catch up with the planet. The resulting retrograde motion of Jupiter after the 6th will increase its distance very slightly from Spica.

On the night of the 15th and 16th the 80% lit waning moon will pass Jupiter. The two are closest at about 5 am on the 16th when the moon will be 3° below Jupiter with Spica 3.6° above the planet, the three forming a line near to dawn.

Morning

Saturn rises about 2.40 am on the 1st and an hour after midnight on the 28th. The planet is in Ophiuchus until the 21st when it moves into Sagittarius. The 32% lit waning moon will be 5° to the left of Saturn on the morning of February 21.

Saturn's ring system is now wide open as seen from the Earth. The planet's north pole is tilted towards us by over 26°. This is sufficient to bring the far edge of the ring system into view over the north pole of Saturn. Also the satellites, visible in a fairly small telescope, will appear scattered around the planet in a pattern changing from night to night.

Mercury rises about an hour and three-quarters before the Sun on February 1 so it should be visible in the morning sky about an hour before sunrise. The planet will then be a low 7° a little to the south of east. On the 1st Mercury is in Sagittarius at magnitude -0.2, it will be a little below the handle of the "teapot". During February Mercury moves out of Sagittarius, first into Capricornus on the 7th and then into Aquarius on the 24th. At the same time, its elongation from the Sun will steadily decrease. As a result the planet will be lost to view in the twilight glow by about the middle of the month.

The moon, as a very thin crescent, will be 5° to the left of Mercury on the morning of the 26th.

Outer Planets

Uranus, at 5.8 to 5.9, remains in Pisces and is best observe early evening. On the 1st about 12.30 am and about 10.30 pm on the 28th. As noted above it is close to Mars at the end of the month giving an easy opportunity to locate the outer planet in binoculars. On the 2nd, the 30% lit waxing moon will be just under 3° to the upper left of Uranus.

Neptune is in Aquarius at magnitude 8.0 throughout February. Nominally in the evening sky, it will be too close to the Sun to observe. It sets just 7 minutes after the Sun on the 28th.

Pluto was at conjunction with the Sun on January 7, so will be moving into the morning sky during February. The planet is still in Sagittarius and will rise at 2.40 am on the 28th.

Minor Planets

(1) Ceres is an early evening object. It starts the month in Pisces but moves across a corner of Cetus starting on the 13th. The asteroid is a 9th magnitude object.

(4) Vesta is also an evening object in February with a magnitude fading from 6.6 to 7.1 during the month. It will move to the west through Gemini and will be between 3 and 4° from beta Gem, Pollux, magnitude 1.2.

Four other asteroids brighten sufficiently to be visible in binoculars during the month. Three of them (9) METIS, (14) IRENE and (29) AMPHITRITE are in Leo, although Irene crosses a spur of Leo Minor from the 3rd to the 12th. The fourth, (15) Eunomia is in Sextans. All four brighten to between magnitude 9.0 and 9.2. Three of them are at opposition during February, Eunomia February 16/17, Irene February 23/27 and Metis the following night. Amphitrite brightens from 9.8 on the 1st to 9.2 on the 28th. It is at opposition in March.

Comets.

Up to 3 comets May be visible in binoculars during February. Magnitudes shown are estimates for the whole comet, the nucleus is likely to be fainter.

P/Encke (2P) is in Pisces fairly close to Venus. It brightens during the month from magnitude 11.4 on the 1st to 5.5 on the 28th. Unfortunately as it brightens so it gets lower in the western early evening sky. By the 28th it will set only 34 minutes after the Sun making it virtually un observable.

P/Honda-Mrkos- Pajdusakova (45P) moves into the morning sky at the beginning of February. On the 8th it will be at magnitude 8.3. Two mornings later (10th) at 8.5 it will 6° to the lower left of alpha Oph (2.1). On the 13th 2° below alpha CrB (2.2) and on the mornings of 15 and 16 Feb at mag 9.2 it will be 12.5°below Arcturus (mag 0.2). Thus it will remain a very low object for NZ observers.

Brian Loader  
New Zealand

The Solar System In January 2017

Dates and times shown are NZDT (UT + 13 hours).

Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

Sunrise, sunset and twilight times in January

                            January  1  NZDT                 January 31  NZDT
                    morning  evening                 morning  evening
       SUN: rise:   5.48am,  set:  8.59pm    rise:   6.22am,  set:  8.44pm
Twilights
  Civil:    starts: 5.18am,  ends: 9.31pm    starts: 5.54am,  ends: 9.13pm
  Nautical: starts: 4.35am,  ends:10.14pm    starts: 5.16am,  ends: 9.51pm
  Astro:    starts: 3.44am,  ends:11.04pm    starts: 4.34am,  ends:10.33pm

January phases of the moon (times as shown by guide)

          First quarter: January  6 at  8.47 am (Jan  5, 19:47 UT)
  Full moon:     January 13 at 12.34 am (Jan 12, 11:34 UT)
  Last quarter   January 20 at 11.13 am (Jan 19, 22:13 UT)
  New moon:      January 28 at  1.07 pm (00:07 UT)

The Earth is at perihelion, its closest to the Sun for the year, on January 4 at 11 pm (NZDT), 10 hours UT. The Earth will then be 0.9833 AU, 147.1 million km, from the centre of the Sun, which will have an apparent angular diameter of 32.53 arc-minute.

The planets in January 2017

Venus remains the obvious bright planet in the evening sky with Mars, much fainter, only a few degrees higher. Mercury will be a morning object visible an hour before sunrise during the second half of the month. Jupiter and Saturn are also morning planets. Jupiter rises just before midnight by the end of January. Saturn will be readily visible to the east by the end of the month.

Evening Planets

Venus will remain brilliant in the evening sky throughout January reaching magnitude -4.7 by the 31st. It will get a little lower in the western sky, setting by 10.30 pm at the end of January. The planet starts January in Aquarius moving on into Pisces on the 23rd.

On the 13th Venus will pass Neptune, magnitude 7.9. At their closest their separation will be 21 arc-minutes, less than the diameter of the full moon. By 10 pm, when the sky should be dark enough to see Neptune in binoculars, the two planets will be 36 arc-minutes apart with Neptune to the left of and slightly higher than Venus

The crescent moon will be a couple of degrees below Venus on January 2.

Mars is a little higher than Venus throughout January, its brightness fading slightly from magnitude 0.9 to 1.1 during the month. It is 12° from Venus on the 1st, the separation decreasing to 5.5° by the 31st. On January 19 Mars will move into Pisces from Aquarius.

Early in January, Mars and Neptune are very close, the separation being only 4.9 arc-minutes on the 1st about 1-6th of the diameter of the full moon. Neptune is then to the lower left of Mars with a magnitude 7.9 so visible in binoculars. There will be no star nearby which could be confused with Neptune.

Mars will move away from Neptune during the following evenings but on the 3rd the two, now 1.5° apart, will be joined by the 25% lit crescent moon. By the time the sky is dark enough to see the planets, the moon will have just moved past them and be about 1° from Mars. A few hours earlier the moon will occult first Neptune and then Mars, events visible from the parts of the north Pacific.

Morning Planets

Jupiter is the brightest planet in the morning sky, it will be joined there by Saturn and Mercury during the month. On the 1st Jupiter rises at 1.25 am, almost 2 hours earlier by the 31st, that is shortly before midnight. In Virgo, Jupiter starts the month 4.4° from Spica. Its slowing, easterly movement brings it to just over 3.5° from the star by the end of the month.

On the morning of the 20th, the moon at last quarter, will be just over 5° from Jupiter and 7° from Spica.

Saturn, emerging into the morning sky after its December conjunction, will rise about 80 minutes before the Sun on the 1st and more than three and a half hours earlier than the Sun on the 31st. The planet is in Ophiuchus at magnitude 0.5.

On the morning of the 25th, the crescent moon will be just over 5° below Saturn as seen from New Zealand.

Mercury also emerges from the Sun into the morning sky following its inferior conjunction at the end of December. At first it will be too close to the Sun to see. The westerly retrograde motion of the planet will move it quite rapidly away from the Sun, so that when stationary on the 9th, it will rise 75 minutes before the Sun. Mercury will also have brightened from magnitude 2.9 to 0.4, so it May be briefly visible very low to the east-south-east before the sky gets too bright to see the planet. It will then be some 6.5° to the lower right of Saturn.

Mercury’s distance from the Sun continues to increase for another 10 days until it reaches its greatest elongation on the morning of the 20th. It will then be 24° from the Sun at magnitude -0.2, rising 100 minutes before the Sun and so readily visible, if low, up to an hour or less before sunrise. The planet continues to be briefly visible at this sort of time for the rest of the month.

The moon, as a very thin crescent, will be 5° to the left of Mercury on the morning of the 26th.

Outer Planets

Uranus, at magnitude 5.8, remains in Pisces and is observable all evening. It will set after midnight, about 12.30 am by the 31st. The moon, just past first quarter, will be just over 4° to the upper right of Uranus on the 6th.

Neptune is in Aquarius at magnitude 7.9 throughout January. It conjunctions during the month with Mars, on the 1st, and Venus, on the 13th are described in the notes for those planets.

Pluto is at conjunction with the Sun on January 7, so is not observable during the month. At conjunction Pluto will be over 33 astronomical units from the Sun and over 34 AU, 5.1 billion km, from the Earth.

Minor Planets

(1) Ceres starts the month in Cetus but moves into Pisces on the 8th. The asteroid fades a little during the month from magnitude 8.6 to 9.0. Its distance from Uranus increases from 7.2 to 9.5° during the month. The asteroid sets just after midnight at the end of January.

(4) Vesta starts January in Cancer moving on into Gemini on the 19th. It ends the month about 3.5° above and to the right of Pollux, beta Gem, mag 1.2. Vesta is at opposition on the 18th when its magnitude will be 6.2

(18) Melpomene is also in Cetus between 11 and 15 degrees from Ceres. The asteroid continues to fade from magnitude 9.7 to 10.3 during January. Melpomene is on the opposite side of Ceres to Uranus. The asteroid is also a few degrees from comet Harrington-Wilson during January.

(9) Metis and (14) IRENE are both in Leo, about 6° apart. Their magnitudes brighten to 9.5 and 9.4 respectively on the 31st. Metis will then be just over 12° to the right of Regulus, mag 1.4, in a direction towards delta Leo, mag 2.5. Irene will be below Metis. They rise about 10.30 pm.

(15) Eunomia also brightens to magnitude 9.5 by the 31st. It will then be in Sextans, 2.5° to the right of alpha Sex, mag 4.5. Eunomia rises just before 9pm.

Comets.

Two reasonably bright comets should be visible in binoculars during January.

P/Honda-Mrkos- Pajdusakova (45P) at magnitude 7.7 is 16° to the lower left of Venus on the 1st. The 9% lit crescent moon will be 5.5° to the right and slightly lower than the comet. At 10 pm the comet will have an 8° altitude, the moon being a degree lower. Subsequent evenings the comet will get lower in the evening sky and soon be lost to view.

D/Harrington-Wilson (D/1952 B1) is in Cetus, magnitude 8.9 on the 1st and 8.6 on the 31st. It will be quite close to the asteroid (8) Melpomene, their separation being about 6° on the 1st, 4° mid month and just over 6° by the 31st. On the 23rd the comet is less than a degree below the star Menkar, alpha Cet, mag 2.5.

Brian Loader  
New Zealand