La Société Guernesiaise Astronomy Section

 Astronomical events in 2008

By David Le Conte

 

 

This year we can look forward to a morning total eclipse of the Moon, a minor partial solar eclipse, and an occultation of Venus.

 

PLANETS

 

The dates of maximum elongations of Mercury are as follows.  It can usually be seen about ten days before and after these dates.  The best dates to observe it in the evening will be the last two weeks of January, and the first three weeks of May, and in the morning the last two weeks of October.

 

22 January                      Evening                

03 March                       Morning

14 May                          Evening

01 July                           Morning

11 September                 Evening

22 October                    Morning

 

Venus, which has been a brilliant object in the pre-dawn sky for the last few months, will soon be lost from view.  It will not re-appear until September, when it will be the ‘Evening Star’ low in the west until the end of the year.  It will be occulted on 01 December (for details, see under the heading “Occultations and conjunctions”, below.)

 

After its opposition in December 2007, Mars disappears in early 2008, not to be seen again for the rest of the year.

 

Jupiter appears in the dawn sky in February, and remains low in Sagittarius for the next rest of the year.  It reaches opposition on 09 July, and then becomes visible in the evening, never reaching much of an altitude. As usual, there will be transit and occultation events involving Jupiter’s moons, details of which can be found on the Sky and Telescope web site, or simulated on software such as StarryNight.

 

Saturn, reaches opposition in Leo on 24 February, and remains visible in the evening until the middle of the year.  It reappears in the morning sky in October.

 

Uranus is at opposition in Aquarius on 13 September at magnitude 6, and Neptune is at opposition in Capricornus on 15 August at magnitude 8.

 

DWARF PLANETS

 

Pluto reaches opposition in Sagittarius on 20 June at magnitude 14.  Ceres does not reach opposition this year.  Eris, at magnitude 19, is beyond the capabilities of most amateur telescopes.

 

ASTEROIDS

 

The brightest asteroid, Vesta, reaches opposition on 30 October in Cetus at magnitude 6.

 

ECLIPSES

 

There will  be a total, although non-central eclipse of the Moon on 21 February. It will start entering the penumbra at 00.35 am, and the umbra at 01.43 am.  Totality will last from 03.00 am to 03.51 am, with mid-eclipse being at 03.26 am.  The Moon will have left the umbra by 05.09 am, and the penumbra by 06.17 am.  All times are in UT.  It will be in Leo during this eclipse, and should be a fine sight, being close to Saturn and Regulus.

 

On 01 August there will be a partial solar eclipse, from 09.35 am to 10.53 am.  Maximum eclipse of 22% will be at 10.13 am.  Times are in BST.

 

On 16 August there is a partial lunar eclipse, from just after moonrise, at 8.35 pm, to 11.44 pm BST.  Maximum eclipse is at 10.09 pm, when 81% of the Moon will be in the Earth’s shadow.

 

OCCULTATIONS AND CONJUNCTIONS

 

Venus will be occulted by the unlit side of the Moon from 3.43 pm on 01 December (in daylight), re-appearing from the crescent-lit side of the Moon an hour after sunset, at 5.17 pm.  During this occultation Jupiter will be just two degrees away, so it should be worth watching.

 

On 13 December, from 9.03 pm to 10.05 pm the third magnitude epsilon Geminorum will be occulted by the Moon.

 

Mercury will be within half a degree of the Moon after sunset on 09 January.  On 01 February Venus and Jupiter will be about half a degree apart.  On the evening of 12 March, and again on the morning of 20 September, the Moon will pass close to the Pleiades.  Mars and the Moon will be close together on 10 May.  Mars and Saturn will be within a degree of each other on the evening of 10 July.  On the evening of 13 August Venus and Saturn are within half a degree.  Two days later, on 15 August, it is Mercury’s turn to be close to Saturn, and on 20 August Mercury is within a degree of Venus.  On 12 September Mars is half a degree from Venus.

 

METEORS

 

The Quadrantids peak on the night of 05/06 January, almost coinciding with New Moon, and so will be very favourable.  The rest of the year does not bode so well, however.  The Perseids peak on the night of 11/12 August, but the Moon, at age 12 days, will badly affect observations of them.  The Leonids too will be washed out with a 19-day-old Moon on 12 November, and the fact that the short peak occurs at midday.  And the Geminids, peaking on 13 December, will be affected by a Full Moon.

 

COMETS

 

Comet Holmes, which unexpectedly flared up to 3rd magnitude in Perseus in October 2007, may still be visible at the beginning of 2008.  Comet Tuttle may well be a binocular or naked-eye object low in the south in early January, disappearing southward by the end of the month.  Comet Boethin may reach 7th magnitude in the evening in December.  For more details of visible comets see the British Astronomical Association Comet Section web page.  It is, of course, ever possible that a new comet may make an unexpected bright appearance.

 

EQUINOXES AND SOLSTICES

 

The following are the dates and times (UT) of the equinoxes and solstices in 2008:

 

Vernal Equinox               20 March                05.48  UT 

 Summer Solstice            21 June                   00.59  BST

 Autumnal Equinox         22 September         16.44  BST

 Winter Solstice              21 December          12.03  UT

 

SATELLITES

 

The International Space Station is regularly visible from Guernsey.  Also of interest are flashes from the Iridium satellites, and periodic launches of the Space Shuttle.  Many other, fainter, satellites appear every night.  Details of the times and directions of visibility can be obtained from the Heavens-Above web site.

 

WEA COURSE

 

The Astronomy Section is running its annual six-week “Star Gazing” course at the Observatory in February and March.  Enrolment is through the Workers Education Association.  As always, it is already fully subscribed.

 

OPEN DAYS

 

The Observatory will be open again for a number of Tuesday evenings during the year.  For details click here.

 

 

CALENDAR OF ASTRONOMICAL EVENTS

 

Month

Date

Time

Event

January

 

All night

Comet Holmes

January

 

 

Comet Tuttle

January

05/06

 

Quadrantid meteor shower

January

09

Evening

Mercury and Moon conjunction

January

22

Evening

Mercury maximum elongation

February

01

Evening

Venus and Jupiter conjunction

February

07

20.00 UT

WEA course starts

February

20/21

01.43

Total eclipse of the Moon

February

24

 

Saturn at opposition

March

03

Morning

Mercury maximum elongation

March

12

Evening

Moon and Pleiades conjunction

March

13

20.00 UT

WEA course ends

March

20

05.48 UT

Vernal Equinox

March

30

01.00 UT

BST starts

May

10

Evening

Mars and Moon conjunction

May

   14

Evening

Mercury maximum elongation

June

20

 

Pluto at opposition

June

21

00.59 BST

Summer Solstice

July

01

Morning

Mercury maximum elongation

July

09

 

Jupiter at opposition

July

10

Evening

Mars and Saturn conjunction

August

01

09.35 BST

Partial eclipse of the Sun

August

11/12

 

Perseid meteor shower

August

13

Evening

Venus and Saturn conjunction

August

15

Evening

Mercury and Saturn conjunction

August

15

 

Neptune at opposition

August

16

20.35 BST

Partial eclipse of the Moon

August

20

Evening

Mercury and Venus conjunction

September

11

Evening

Mercury maximum elongation

September

12

Evening

Mars and Venus conjunction

September

13

 

Uranus at opposition

September

20

Morning

Moon and Pleaides conjunction

September

22

16.44 BST

Autumnal Equinox

October

22

Morning

Mercury maximum elongation

October

26

02.00 BST

BST ends

October

30