Shop at Amazon US

Contributions

If you like the website and want to contribute to the running costs then please do so below. All contributions are most welcome.

PayPal - The safer, easier way to pay online.

Dwarf planet Ceres and Vesta the brightest asteroid both reach opposition in April and are currently positioned close together in Virgo, just northeast of Spica (α Vir) and Mars. Both objects are visible in binoculars as they travel quickly against the "fixed" background stars; their movements can even be tracked on a night-by-night basis.

Discovery

On January 1, 1801, Italian Catholic priest and astronomer Giuseppe Piazzi discovered Ceres, originally believing it to be a comet. This new object between the orbits of Mars and Jupiter was initially classified as a planet and subsequently given its own planetary symbol. However with further discoveries all in the same region of the Solar System, the general term asteroids were coined to describe them. Much later in 2006, the International Astronomical Union (IAU) defined a new classification of dwarf planet of which Ceres is now a member. It has a diameter of 975 kilometres (610 miles) and can peak at apparent magnitude +6.7, beyond naked eye visibility but easy with binoculars.

Hubble Telescope image of Ceres in 2004 (NASA,ESA and J. Parker (Southwest Research Institute))

Vesta was the fourth asteroid to be discovered on March 29, 1807 by German astronomer Heinrich Wilhelm Olbers. Despite being only the third largest body in the main asteroid belt - diameter 530 kilometres (330 miles) - Vesta is the brightest asteroid. It appears brighter than Ceres and the slightly larger Pallas since its approaches closer to Earth and has a much higher reflective surface. At favourable oppositions, the maximum apparent magnitude of Vesta is +5.1, putting it within naked eye visibility.

Vesta imaged on September 5, 2012 by the departing NASA Dawn spacecraft (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

Location

This year Vesta reaches opposition on April 13th (mag. +5.8) with Ceres reaching opposition on April 15th (mag. +6.9). The pair have not been this close together in the night sky - during an opposition period - for hundreds of years. During April they are positioned about 16 degrees northeast of Spica (α Vir - mag. +1.0). The much brighter red-orange Mars (mag. -1.5) starts the month just north of Spica but then quickly moves out westwards due its retrograde motion. Like Mars, Ceres and Vesta are also currently moving retrograde but since they are more distant they don't travel as fast against the constellation backdrop.

During April, Ceres is positioned 2.5 degrees northeast of Vesta with the latter being about 3 times brighter. Theoretically Vesta can be seen with the unaided eye, but this requires very dark skies. The two objects are so close together that they can be seen in the same binocular field of view.

At opposition, Vesta and Ceres are 1.232 AU (approx. 184.3 million kilometres or 114.5 million miles) and 1.644 AU (approx. 245.9 million kilometres or 152.8 million miles) distant from Earth respectively. Later on July 5th, Ceres and Vesta will be separated by just 10 arc minutes but by then they will have faded to magnitudes +7.4 and +6.2 respectively.

Night sky positions of Ceres, Vesta and Marsduring April 2014

Night sky positions of Ceres, Vesta and Mars during April 2014 - pdf format

Ceres Data Table - April 2014

DateRA (J2000)DEC (J2000)Apparent MagnitudeConstellation
April 0114h 04m 45s02d 38m 44s+7.1Virgo
April 0214h 04m 01s02d 42m 41s+7.1Virgo
April 0314h 03m 15s02d 46m 35s+7.1Virgo
April 0414h 02m 28s02d 50m 25s+7.1Virgo
April 0514h 01m 41s02d 54m 10s+7.0Virgo
April 0614h 00m 53s02d 57m 51s+7.0Virgo
April 0714h 00m 04s03d 01m 26s+7.0Virgo
April 0813h 59m 14s03d 04m 56s+7.0Virgo
April 0913h 58m 24s03d 08m 20s+7.0Virgo
April 1013h 57m 33s03d 11m 38s+7.0Virgo
April 1113h 56m 42s03d 14m 50s+7.0Virgo
April 1213h 55m 50s03d 17m 54s+7.0Virgo
April 1313h 54m 58s03d 20m 52s+7.0Virgo
April 1413h 54m 05s03d 23m 42s+6.9Virgo
April 1513h 53m 12s03d 26m 24s+6.9Virgo
April 1613h 52m 19s03d 28m 58s+6.9Virgo
April 1713h 51m 26s03d 31m 24s+6.9Virgo
April 1813h 50m 33s03d 33m 42s+7.0Virgo
April 1913h 49m 40s03d 35m 50s+7.0Virgo
April 2013h 48m 47s03d 37m 50s+7.0Virgo
April 2113h 47m 53s03d 39m 40s+7.0Virgo
April 2213h 47m 01s03d 41m 21s+7.0Virgo
April 2313h 46m 08s03d 42m 52s+7.0Virgo
April 2413h 45m 15s03d 44m 13s+7.0Virgo
April 2513h 44m 23s03d 45m 24s+7.0Virgo
April 2613h 43m 32s03d 46m 25s+7.1Virgo
April 2713h 42m 40s03d 47m 15s+7.1Virgo
April 2813h 41m 50s03d 47m 54s+7.1Virgo
April 2913h 40m 59s03d 48m 23s+7.1Virgo
April 3013h 40m 10s03d 48m 41s+7.1Virgo

Vesta Data Table - April 2014

DateRA (J2000)DEC (J2000)Apparent MagnitudeConstellation
April 0113h 55m 38s01d 37m 25s+5.9Virgo
April 0213h 54m 52s01d 43m 42s+5.9Virgo
April 0313h 54m 05s01d 49m 56s+5.9Virgo
April 0413h 53m 16s01d 56m 07s+5.9Virgo
April 0513h 52m 27s02d 02m 15s+5.9Virgo
April 0613h 51m 37s02d 08m 18s+5.8Virgo
April 0713h 50m 45s02d 14m 16s+5.8Virgo
April 0813h 49m 53s02d 20m 08s+5.8Virgo
April 0913h 49m 00s02d 25m 54s+5.8Virgo
April 1013h 48m 07s02d 31m 34s+5.8Virgo
April 1113h 47m 13s02d 37m 07s+5.8Virgo
April 1213h 46m 18s02d 42m 32s+5.8Virgo
April 1313h 45m 23s02d 47m 50s+5.8Virgo
April 1413h 44m 28s02d 52m 58s+5.8Virgo
April 1513h 43m 32s02d 57m 58s+5.8Virgo
April 1613h 42m 36s03d 02m 48s+5.8Virgo
April 1713h 41m 40s03d 07m 28s+5.8Virgo
April 1813h 40m 44s03d 11m 58s+5.8Virgo
April 1913h 39m 47s03d 16m 16s+5.8Virgo
April 2013h 38m 51s03d 20m 24s+5.8Virgo
April 2113h 37m 55s03d 24m 20s+5.8Virgo
April 2213h 36m 60s03d 28m 04s+5.8Virgo
April 2313h 36m 04s03d 31m 36s+5.8Virgo
April 2413h 35m 09s03d 34m 55s+5.8Virgo
April 2513h 34m 15s03d 38m 01s+5.9Virgo
April 2613h 33m 21s03d 40m 54s+5.9Virgo
April 2713h 32m 28s03d 43m 33s+5.9Virgo
April 2813h 31m 35s03d 45m 58s+5.9Virgo
April 2913h 30m 44s03d 48m 09s+5.9Virgo
April 3013h 29m 53s03d 50m 06s+5.9Virgo