20 May 2011

Finding Neptune and Uranus

In the early morning hours these days we can spot Mercury, Venus, Mars and Jupiter without any optical aid. But there are two giants who rise early but require little optical help, these giants are, planets Neptune and Uranus.

If we look at the eastern sky at around 3am the planet Neptune will be at an altitude of 40degree from the eastern horizon in the constellation of Aquarius. One advantage of spotting the planet at this time of 3am is that we have bright 1st magnitude star Fomalhaut as a reference starting point. Looking at south-east the star Fomalhaut can be easily found as there are no bright 1st magnitude stars other than Fomalhaut in that region.

We will start by locating the star Fomalhaut, the sky charts below will be of good help. 
 The sky is for 3:30am.

Once we have Fomalhaut in the field of binocular or telescope, we move up 21 degrees and locate delta Capricorni, follow the dotted yellow line.  

Delta Capricorni is an 2.8 magnitude star and can be easily found. Now from Delta Capricorni we move to Iota Aquarii.

Iota Aquarii  is little dimmer at 4.2magnitude and it is around 5degrees NE from Delta Capricorni. From Iota Aquarri we move 2.3degrees North and find the star 38 Aquarii at magnitude 5.4.

Neptune lies just 21 minutes east of 38 Aquarii (below 38 Aquarii) and is easy to spot. At opposition the distance from Earth 4347.31 million(km). The Apparent Magnitude of the planet is 7.8 magnitude.

Rising times of Neptune:

28 May 2011 00:20
05 Jun 2011 23:45
13 Jun 2011 23:13
21 Jun 2011 22:42
29 Jun 2011 22:10
07 Jul 2011 21:38
15 Jul 2011 21:05
23 Jul 2011 20:34
31 Jul 2011 20:02
08 Aug 2011 19:30


Uranus is easy to find as the planet is bright at 5.9 magnitude. These charts will help in locating the planet. We all are very familiar with the Great Square, using the two stars Alpheratz and Algenib and moving towards south, its easy to find the planet Uranus. At opposition the distance  2719 million (km) and shines at a 5.5magnitude.

The sky at 3:30am

Rising Times of Uranus:

28 May 2011 02:11:00 AM
05 Jun 2011 01:40:00 AM
13 Jun 2011 01:10:00 AM
21 Jun 2011 12:39:00 AM
29 Jun 2011 12:08:00 AM
07 Jul 2011 11:32:00 PM
15 Jul 2011 11:01:00 PM
23 Jul 2011 10:29:00 PM
31 Jul 2011 09:57:00 PM
08 Aug 2011 09:25:00 PM

Happy spotting the planets and clear skies.

Star chart prepared with Stellarium 

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