THE SOLAR SYSTEM IN SEPTEMBER 2018

 Dates and times shown are NZST (UT + 12 hours) until NZDT (UT + 13 hours) starts on the last Sunday of September (30th in 2018). On the Sunday, 2am becomes 3am.
The southern spring equinox is on September 23 with the Sun crossing the celestial equator just before 2pm.
Rise and Set times are for Wellington. They will vary by a few minutes elsewhere in NZ. Data is adapted from that shown by GUIDE 9.

THE SUN and PLANETS in SEPTEMBER 2018, Rise & Set,  Mag. & Cons.
      September  1    NZST         September 30    NZDT  
      Mag  Cons    Rise    Set     Mag  Cons    Rise    Set
SUN  -26.7  Leo   6.44am  5.58pm  -26.7  Vir   6.55am  7.27pm
Merc  -0.9  Leo   6.06am  4.32pm   -1.0  Vir   7.15am  8.01pm
Venus -4.6  Vir   8.14am  9.51pm   -4.8  Vir   7.43am 10.33pm
Mars  -2.1  Cap   2.01pm  5.33am   -1.3  Cap   1.49pm  4.52am
Jup   -1.9  Lib   9.35am 11.43pm   -1.8  Lib   8.55am 11.13pm
Sat    0.4  Sgr  12.19pm  3.21am    0.5  Sgr  11.26am  2.29am
Uran   5.7  Ari  10.16pm  9.01am    5.7  Ari   9.18pm  8.05am
Nep    7.8  Aqr   6.17pm  7.13am    7.8  Aqr   5.19pm  6.17am
Pluto 14.4  Sgr   1.32pm  4.29am   14.4  Sgr  12.37pm  3.34am

          September  1  NZST         September 30  NZDT
Twilights    morning     evening        morning     evening
Civil:    start 6.19am, end 6.24pm   start 6.30am, end 7.53pm
Nautical: start 5.47am, end 6.56pm   start 5.57am, end 8.26pm
Astro:    start 5.15am, end 7.28pm   start 5.24am, end 8.59pm

      SEPTEMBER PHASES OF THE MOON, times NZST (& UT)
 
  Last quarter   September  3 at  2.37pm (02:37 UT)
  New moon:      September 10 at  6.01am (Sep  9 18:01 UT)
  First quarter: September 17 at 11.15am (Sep 16 23:15 UT)
  Full Moon:     September 25 at  2.52pm (02:52 UT)

PLANETS in September 2018

MERCURY will be poorly placed for viewing throughout September. It starts the month as a morning object rising 38 minutes before the Sun. Over the next 3 weeks its angular distance from the Sun decreases until Mercury is at superior conjunction on the 21st. At its closest, the planet will be 1.5° north of the Sun. It will actually be 207.6 million km from the Earth and 57.5 million km beyond the Sun.

After conjunction, Mercury becomes an evening object setting after the Sun, but only by 34 minutes by the 30th.

VENUS will still dominate the early evening sky in September reaching a magnitude -4.8 by the end of the month. Shadows cast by the planet may be visible on a light coloured surface away from artificial light. With the start of NZDT, Venus will not set until 10.33 pm on the 30th.

On the 1st Venus will be only 1.5° from Spica, alpha Virginis, magnitude 1.1.

MARS starts September as an evening object on the border of Sagittarius and Capricornus. At magnitude -2.1 it will still be slightly brighter than Jupiter. During September, Mars dims a little to end the fainter by half a magnitude at the end of the month.

The moon is just over 5° from Mars on the evening of September 20.

JUPITER remains in Libra during September slowly moving away from alpha Lib. The crescent moon will be 4.5° to the right of the planet on the evening of the September 14.

SATURN continues to move through Sagittarius during September. On the evening of the 17th the moon, just past first quarter, will be some 5° below Saturn at midnight. The two are closest after they set in NZ.

URANUS rises at 10.16pm on the 1st. On the 30th it rises an hour earlier, NZDT. The planet will be slow moving in Aries. The moon, just past full, we be 4° from the planet on the 27th.

NEPTUNE in Aquarius is at opposition on September 8. The moon, a couple of days before full, is about 3° from Neptune on the 23rd.

PLUTO, still in Sagittarius is visited by the moon on the 19th. In fact the two are closest about midday, slightly under 2° apart. By 8pm at the time Pluto is highest for NZ, the two are nearly 4° apart. Pluto is stationary on the 30th.

 

BRIGHTEST ASTEROIDS in SEPTEMBER, magnitude, constellation, time of transit

             SEPTEMBER 1  NZST      SEPTEMBER 30 NZDT  
             Mag  Cons   transit    Mag  Cons   transit
(1)  Ceres   8.8   Vir    1.44pm    8.6   Vir    1.37pm
(2)  Pallas  8.9   Sex   11.21am    9.0   Sex   11.25am
(3)  Juno    8.9   Tau    5.15am    8.3   Tau    4.48am
(4)  Vesta   7.0   Oph    7.20pm    7.5   Sgr    7.03pm

CERES sets 7.21 pm on September 1 about 85 minutes after the Sun. It gets closer to the Sun during the month. September 30 sees Ceres only 2 days short of conjunction.

PALLAS, a morning object rises, about 90 minutes before the Sun on the 1st. The interval increases only 10 minutes by the 30th.

JUNO is essentially a morning object rising just before midnight on the 1st and at 11 pm on the 30th.

VESTA moves past Saturn during September. The asteroid moves into Sagittarius from Ophiuchus on the 5th and is closest to Saturn on the 25th and 26th when they are just under 3° apart. Vesta sets at 2.48 am NZDT on the 30th.

Brian Loader

 

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