Webmaster  © Paul L Money 2012

Chasing Asteroids and Dwarf Planets

For 2012 we have two Asteroids and a Dwarf planet, that may be viewable with at least binoculars, that get brighter than mag 10 at opposition: 1 Ceres, 4 Vesta and 2 Pallas.

We briefly begin with Ceres and Vesta as, for a short time, they are visible in the evening sky. Vesta begins the year in Aquarius not too far from Neptune. On the night of Jan 9th/10th mag 8.2 Vesta lies almost on top of the mag 4 star Tau 2 Aquarii making it easy to locate. Vesta moves quickly through Aquarius but is overwhelmed by the encroaching evening twilight by late February. Meanwhile Ceres starts the year just in Aquarius at mag 9.1 and rapidly moves into Cetus with a brief slip into Pisces at the end of January. It moves through Cetus again for February and into March lying south of much brighter Uranus but it too is then overwhelmed by the evening twilight. Vesta is in Solar conjunction on April 10th whilst Ceres is in Solar conjunction on April 26th.  

We will return to both later in the year. Sadly for most of the Spring and some of the Summer months there are no easy/bright minor or dwarf planets to view until Pallas comes to the fore in late July (right). The path of Pallas from July 1st to the end of the year is shown at left. On July 1st it is mag 10 and it swings round past the area with Uranus in as it moves retrograde through Cetus from August 9th. Pallas brightens to a respectable mag 8.3 by the time it reaches opposition on September 25th. A few days after this on the evenings of the 28th and 29th Pallas glides close by to mag 3.5 iota Ceti making it easier to locate the minor planet.  Pallas remains visible and continues to move down into lower Cetus passing very close to the 6.2 mag star 1 Ceti on the nights of Nov 3rd / 4th. It spends a brief few days mid month in Aquarius before heading back into Cetus and continues to fade slowly to mag 9.6 by the end of the year.

We now turn back to Ceres and Vesta. They make our life easier by staying in the same general area of sky and what an area it is, Taurus the bull, Gemini the twins and Orion the hunter. Although the skies will be light both Ceres and Vesta should be visible in binoculars in the light morning skies of early August. Vesta begins in the Hyades open cluster and slides past Aldebaran on the morning of Aug 6th although I don’t think you will confuse the two, Vesta is mag 8.3 and Aldebaran is mag 1! On Aug 1st Ceres lies close to the mag 5.1 star 97 Tauri but Ceres will be mag 9.1 so again no confusion. Jupiter also lies above the Hyades cluster and remains in this area as a beacon to guide you to both Ceres and Vesta for the rest of the year. Initially Venus is also near Zeta Tauri for the first few days of August but rapidly moves away leaving the rest behind.  Ceres sweeps south past Zeta Tauri in early September and just as it reaches a stationary point on Oct 31st it lies very close to mag 3.3 Eta Geminorum. From Nov 20th until Nov 25th it also passes south of the star cluster M35 for a visual and photographic treat as shown at right. Ceres is retrograding and brightening now and by opposition on December 18th it is mag 7 and visible all night. Meanwhile Vesta is slightly brighter and reaches mag 6.8 when it is at opposition on December 9th as it too retrogrades, in this case looking as though it is heading back towards the Hyades. It doesn’t reach them but does lie just a few degrees away from Aldebaran at the end of the year forming a triangle with the Red eye of the bull and Jupiter. Note that Ceres and Vesta were omitted from the Jupiter chart page for clarity.