THE SOLAR SYSTEM IN SEPTEMBER 2021

Dates and times shown are NZST (UT + 12 hours) up to September 25. NZDT begins on Sunday 26, nominally at 2am NZST, when clocks should be moved forward 1 hour to 3am NZDT (UT + 13 hours).

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 9.1.

The southern SPRING EQUINOX is on September 23 with the Sun moving south across the equator at about 7.20am.

THE SUN and PLANETS in SEPTEMBER 2021, Rise & Set  Mag. & Cons.
          SEP 1     NZST              SEP 30     NZDT  
      Mag  Cons    Rise    Set     Mag  Cons    Rise    Set
SUN  -26.7  Leo   6.43am  5.58pm  -26.7  Vir   6.54am  7.27pm
Merc  -0.1  Vir   7.36am  7.59pm    1.4  Vir   7.20am  9.03pm
Venus -4.0  Vir   8.16am  9.20pm   -4.2  Lib   8.38am 11.22pm
Mars   1.8  Leo   7.18am  6.57pm    1.7  Vir   7.05am  7.38pm
Jup   -2.9  Cap   4.35pm  6.26am   -2.7  Cap   3.26pm  5.24am
Sat    0.3  Cap   3.05pm  5.35am    0.5  Cap   2.05pm  4.38am
Uran   5.7  Ari  11.19pm  9.33am    5.7  Ari  10.22pm  8.37am
Nep    7.8  Aqr   6.51pm  7.29am    7.8  Aqr   5.53pm  6.33am
Pluto 14.5  Sgr   1.53pm  4.56am   14.5  Sgr   1.01pm  4.01am

                SEP 1  NZST             SEP 30  NZDT
TWILIGHTS    morning     evening       morning      evening
Civil:    start 6.18am, end 6.24pm   start 6.29am, end  7.53pm
Nautical: start 5.46am, end 6.56pm   start 5.57am, end  8.26pm
Astro:    start 5.14am, end 7.28pm   start 5.23am, end  8.59pm

   SEPTEMBER PHASES OF THE MOON, times NZST & UT (NZDT after Sep 26)
  New Moon:      Sep  7 at 12.52pm (00:52 UT)
  First quarter: Set 14 at  8.40am (Sep 13,20:40 UT)
  Full Moon:     Sep 21 at 11.55am (Sep 20,23:55 UT)
  Last quarter   Sep 29 at  2.57pm (01:57 UT)

THE PLANETS in SEPTEMBER 2021

MERCURY is well placed for evening viewing during September. It is at its greatest easterly elongation from the Sun on September 14. Mercury then sets 2 hours and 20 minutes after the Sun. An hour after sunset it will be 16° up, almost due west. Mercury's magnitude will be 0.1.

On September 9, at ca 7pm, Mercury will be 6.6° to the left of a very thin crescent moon, on the 21st the planet will be just under 1.5° to the left of the first magnitude star, Spica and on the 27th Mercury is stationary and then starts retracing its path back towards Spica.

VENUS continues to move up in the western evening sky during September. It sets more than 4 hours after the Sun on the 30th. at 11.22pm (NZDT) for Wellington. At that stage it will be about 45° from the Sun.

On the 6th, Venus will be just over 1.5° to the right of Spica. Compare to Mercury on the 21st. On the 10th, the crescent moon will be just over 4° to the right of Venus. On the 18th, Venus moves into Libra.

MARS remains an evening object during September. Just. On the 1st the planet will be 10° up when the Sun sets at about 6pm. Mars itself then sets an hour later. On the 30th Mars sets only 11 minutes after the Sun, The two are then less than 3° apart.

It won't be a good month for observing Mars.

JUPITER and SATURN are both in Capricornus at present. The moon passes them on successive nights during September. Saturn on the 17th and Jupiter on the 18th. In both instances the planets are just over 3.5° to the left of the moon as seen early evening.

Both planets set well after midnight, making them well placed for evening viewing.

URANUS and NEPTUNE

Uranus does not rise until late evening, so is best viewed as a morning object. Neptune, on the other hand, is at opposition on the 14th, so is at its brightest and in the sky all night.

The full moon is 3.5° from Neptune on the 20th with planet to the lower left of the moon. On the morning of the 25th, the moon, now a little past full, will be less than half a degree (the moon's apparent diameter) above Uranus at 5am, an hour before sunrise.

PLUTO rises early afternoon during September, so is very much an evening object although it doesn't set until well after midnight.

POSSIBLE BINOCULAR ASTEROIDS in SEPTEMBER

                  SEPT 1 NZST          SEPT 30 NZDT  
                Mag  Cons  transit    Mag  Cons  transit
 (1) Ceres      8.7   Tau   6.06am    8.3   Tau   5.27am
 (2) Pallas     8.7   Psc  12.55am    8.9   Aqr  11.40pm
 (4) Vesta      7.9   Vir   3.02pm    7.9   Vir   3.02pm
 (6) Hebe       9.1   Sgr   8.50pm    9.5   Sgr   8.12pm
(12) Victoria   9.3   Aql   9.44pm   10.1   Aql   9.06pm
(89) Julia      9.0   Aqr  11.31pm    9.6   Aqr  10.17pm

CERES is a morning object in Taurus during September. It rises at 12:57 am on the 1st and 12.21 am (NZDT) on the 30th. Ceres will be crossing the Hyades at first, going on to a close pass of Aldebaran mid month. On the morning of the 14th when at their closest, the two will be less than a degree apart. Ceres will then be at magnitude 8.6, to the upper right of Aldebaran at 3am.

PALLAS is at opposition on September 9 with a magnitude 8.5. It rises at 6.57 pm on the 1st, to set 12 hours later. On the 30th it rises at 5.20pm NZDT. The asteroid moves from Pisces into Aquarius on the 24th.

VESTA, as an evening object, will be just over 5° to the right of Venus at the beginning of September. Over the following evenings Venus will draw ahead of the asteroid. On the 10, the crescent moon, at its closest to Venus for the month, will also be 5° above Vesta. On September 30 Vesta sets at 9.38 pm, NZDT.

HEBE, in Sagittarius, it is well placed in the evening sky setting well after midnight. On the 1st it sets at 4 am and at 3.38 am NZDT on the 30th.

VICTORIA at magnitude 9.4 is an evening object, setting, like Hebe, well after midnight. Victoria is some 20° from Hebe the two being at similar altitudes. By the 30th Victoria will have faded to magnitude 10.1

JULIA is observable much of the night, it rises before sunset on the 1st, setting the following morning at 5.35am. By the end of September it will have faded to magnitude 9.6, setting at 4.16 am NZDT.

Brian Loader

 

 

 

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