Meet the night sky’s newest ‘double star’!
It’s only a made-up one and temporary pairing, but Saturn and the star Gamma Virginis, also known as Porrima, make one of the most realistic close pairs of ‘stars’ in the night sky this season. Their pairing closely resembles a telescopic view of a true double star.
The beauty of this close pairing is that Porrima itself is a true binary or double star, making its proximity to Saturn a ‘double double’ delight.
As of this month, the two are separated by a gap of just 1.7″ of arc — a quite small separation. Remember that a second of arc is equal to 1/60 of a minute or 1/3600 of a degree. For reference, the full moon is 1/2 degree or 30 minutes of arc in diameter.
Saturn is easy enough to find. Wait until an hour and a half after sunset, then look for it high in the south-southwest about 15 degrees from Spica. (Saturn will be just a tad brighter and should look yellow compared to Spica’s blue.) For the naked eye observer, watching Saturn and Porrima during June of 2011 provides a terrific opportunity to see a planet in retrograde motion – then pause, then swing back in its normal eastward path against the background stars. For the small telescope user it’s even better. Porrima is a stunning double star when seen in a back-yard telescope – and Saturn, with its rings, the most awesome planet in a small telescope.
Camera used: Panasonic Lumix Digital Camera (7mm focal length, f/3.1, ISO-80 at 60 sec. exposure)
You can view a nice close up image of Saturn and Porrima here.