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Royal Astronomical Society of New ZealandThe Brighter Asteroids in 2008: (2) Pallas |
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Royal Astronomical Society of New ZealandThe Brighter Asteroids in 2008: (2) Pallas |
Chart for Pallas July to September 2008 Chart for Pallas October 2008 to February 2009 Positional data for Pallas
Pallas is at opposition on 4 December 2008 when it will reach magnitude 8.0. The asteroid brightens to magnitude 9.0 during July 2008 and remains brighter than this magnitude through until November 2009.
In July Pallas moves into Eridanus and then swings across the constellation until on September 11 it crosses into Lepus. On that day it will be about 4° from the 0.28 magnitude star Rigel in Orion. The easterly motion of the asteroid will slow while it moves considerably further south due to its highly inclined orbit.
Pallas reaches a "stationary" point in its orbit on October 29 when its easterly motion stops and reverses to become retrograde or westerly. It will in fact still be be moving to the south as can be seen on the second chart. A few days later it enters Columba where it reaches opposition on December 4. Pallas will then be 2.28 AU from the Sun and 1.57 AU from the Earth. The distance from the Sun is fairly close to its minimum distance, 2.14 AU. Hence the Asteroid will be quite bright. Pallas's highly inclined orbit also brings it well south of the equator, so it will be high in NZ skies, almost overhead at transit in the north of the country.
A few days after opposition, Pallas, still moving to the west, will enter Caelum. At the same time it reaches its most southerly point in the sky, almost 33° south of the equator.
Pallas has a diameter of about 524 km making it the third asteroid in size, only 6 km less than Vesta. The orbital period is 4.62 years and the distance of the asteroid from the Sun ranges from 2.14 AU to 3.41 AU. The asteroid's orbit is highly inclined at 34.8° to the ecliptic with an eccentricity 0.23. The effect of the high inclination can be seen in 2008 when at opposition Pallas has a declination nearly 33° south, 55° south of the ecliptic.
As its number implies, Pallas was the second Minor Planet or Asteroid to be discovered. The discoverer was H W Olbers in 1802 at Bremen.
The chart is a southern hemisphere view with north at the bottom and east to the right. Stars to magnitude 9.0 are shown, which is about the limiting magnitude of 50 mm aperture binoculars. Magnitudes are marked (without a decimal point) for stars brighter than 5.5.
The circle on the chart represents a field of view 5° in diameter, a fairly typical field of view for binoculars.
The chart is a southern hemisphere view with north at the bottom and east to the right. Stars to magnitude 9.0 are shown, which is about the limiting magnitude of 50 mm aperture binoculars. Magnitudes are marked (without a decimal point) for stars brighter than 5.5.
The circle on the chart represents a field of view 5° in diameter, a fairly typical field of view for binoculars.
| Date 2007 | R.A hr min | Dec nbsp;° ' |
Mag. | Const |
| Jul 12 | 03 35.1 | -01 13 | 9.6 | Tau |
| Jul 22 | 03 51.0 | -02 02 | 9.5 | Eri |
| Aug 1 | 04 06.5 | -03 06 | 9.4 | Eri |
| Aug 11 | 04 21.4 | -04 29 | 9.3 | Eri |
| Aug 21 | 04 35.6 | -06 10 | 9.2 | Eri |
| Aug 31 | 04 48.9 | -08 10 | 9.1 | Eri |
| Sep 10 | 05 00.9 | -10 28 | 8.9 | Eri |
| Sep 20 | 05 11.5 | -13 04 | 8.8 | Lep |
| Sep 30 | 05 20.2 | -15 54 | 8.7 | Lep |
| Oct 10 | 05 26.8 | -18 56 | 8.5 | Lep |
| Oct 20 | 05 30.8 | -22 02 | 8.4 | Lep |
| Oct 30 | 05 31.9 | -25 04 | 8.2 | Lep |
| Nov 9 | 05 30.1 | -27 51 | 8.1 | Col |
| Nov 19 | 05 25.4 | -30 11 | 8.0 | Col |
| Nov 29 | 05 18.2 | -31 53 | 8.0 | Col |
| Dec 9 | 05 09.7 | -32 47 | 8.0 | Col |
| Dec 19 | 05 00.9 | -32 48 | 8.0 | Cae |
| Dec 29 | 04 53.2 | -31 58 | 8.0 | Cae |
| Jan 8 | 04 47.7 | -30 21 | 8.1 | Cae |
| Jan 18 | 04 45.1 | -28 06 | 8.1 | Eri |
| Jan 28 | 04 45.7 | -25 25 | 8.2 | Eri |
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