Uranus, the seventh planet from the Sun is now becoming better placed for observation as it heads towards October's opposition. During July, the distant planet shines at magnitude +5.8 amongst the faint stars of Pisces, positioned just southeast of the well-known "Great Square of Pegasus".
The planet is visible to the naked eye from a dark site. However, most people will require at least a pair of binoculars to find Uranus, but this is not too difficult once one is familiar with the stars of western Pisces.
The first area of interest to locate is 10 degrees south of the base of the Square of Pegasus. Here lies a circlet of six, mainly 4th magnitude stars, which form the southern fish of Pisces. From here, move about 20 degrees east to star delta (δ) Psc (mag. 4.4). Located a further 3.5 degrees south of this star is Uranus.
At the start of July, Uranus rises in the east during the early hours of the morning, improving to before midnight by months end. The planet then remains visible for the remainder of the night.
On July 18th, Uranus reaches its first stationary point, after which it begins retrograde motion, although since it is so distant from Earth, noticing it move against the fixed background stars requires some patience and observing over at least two, ideally well-spaced apart, nights!
Since Uranus has an apparent diameter of only 3.6 arc seconds, it appears small through amateur telescopes. However, it displays a striking green colour and at magnifications of 100-150x the planet disk is easily apparent, although distinguishing any surface details is difficult.
On July 27th, the 68% illuminated waning gibbous Moon passes 3 degrees north of Uranus.
Uranus July 2013 Data Table
|Date||Right Ascension||Declination||Apparent Magnitude||Apparent Size||Illumination (%)||Distance from Earth (AU)||Constellation|
|July 01, 2013||00h 46m 02.0s||04d 11m 12.6s||5.8||03.5"||100||20.075||Pisces|
|July 06, 2013||00h 46m 14.8s||04d 12m 23.7s||5.8||03.5"||100||19.991||Pisces|
|July 11, 2013||00h 46m 23.2s||04d 13m 06.6s||5.8||03.5"||100||19.908||Pisces|
|July 16, 2013||00h 46m 27.1s||04d 13m 20.9s||5.8||03.6"||100||19.825||Pisces|
|July 21, 2013||00h 46m 26.5s||04d 13m 07.0s||5.8||03.6"||100||19.743||Pisces|
|July 26, 2013||00h 46m 21.4s||04d 12m 25.2s||5.8||03.6"||100||19.664||Pisces|
|July 31, 2013||00h 46m 12.0s||04d 11m 15.9s||5.8||03.6"||100||19.586||Pisces|