A guide to keep you informed about the night sky over Oneonta, NY, brought to you by the astronomer at the SUNY College at Oneonta.

Wednesday, February 8, 2012

See Uranus while it's easy to find!

For thousands of years, people have been familiar with planets visible in the night sky. Jupiter and Venus stand out dramatically, Saturn and Mars are also easily seen, and even Mercury can be observed on those (albeit brief) times it emerges from the Sun's glare. However, Uranus and Neptune are a different story. The first planet to be discovered with a telescope, Uranus (pronounced "YOOR-in-us") shines faintly right around the limit for naked-eye detection. What this means is that if you have extraordinary vision, and know precisely where to look, you may be able to detect its faint glow without optical aid if you are in an absolutely dark location - but most likely you will need some sort of assistance. In the case of Uranus, simple binoculars will work.


Being so faint, it can be somewhat challenging to locate the greenish-blue planet among the background stars. Fortunately, nature is giving us a great opportunity to find it using another solar system object: Venus. Venus happens to be extremely easy to find in the sky right now - just look to the west after sunset and this yellow planet is the brightest point of light you'll see.

Now go grab your binoculars, or a telescope if you have one. On February 9th, Uranus will appear right next to our brightest neighbor in the sky (to the South). The image below shows its position on the evening of February 9th as it would appear looking westward (meaning north is to the upper-right and east is to the upper-left). In red are shown the planets' orbits, which you can use to detect Uranus on any of the other upcoming nights as well. Uranus moves very slowly compared to Venus, so even if Venus has moved with respect to the background stars, you can still use the background stars to identify Uranus.


If you're using binoculars, this is how the image should appear. If you're using a telescope, be careful: the optical system of most telescopes will flip the image upside down unless you are using a diagonal mirror to hold your eyepiece. Orient the image above accordingly.

Happy planet hunting!