Pi Lupi (HJ 4728)

Click above image for larger version

Observation Notes:

If you live near 35 degrees North Latitude, and enjoy overcoming the adversity of observing far southern objects, you may want to give the double star Pi Lupi a try. This pair rises no more than 8 degrees above the horizon where I live. Unlike Gamma Velorum, it is a fairly close double. SItting in the mush above the neighbor’s houses, I had to be very patient to catch glimpses of the two components as separate, swimming points. Discerning color was also difficult with all the distortion, but overall the pair had a bluish white appearance. I estimated a position angle of either 60 or 240 degrees, depending on which was the primary. The Washington Visual Double Star Catalog gives a 1983 value of 70.5 degrees, and a separation of 1.5 arc seconds. The sketch above contains a frozen detail to give you an idea of what the mushy view looked like in general. Clicking the image for the large version may help see that inset better.

Subject Pi Lupi (HJ 4728)
Classification Double Star
Position (J2000) Lupus [RA: 15:05:07 / Dec: -47:03:04]*
Position Angle* 70.5° (1983)
Separation* 1.5″ (1983)
Magnitudes* 4.7; 4.8
Spectral Types* B5; B5
Date/Time JAN 26, 2007 – 06:40 AM MST (JAN 26, 2007 – 13:40 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 10 mm + 2X Barlow (240X)
Conditions Clear, calm, 18° F
Seeing 2/10 Pickering
Transparency NELM Mag ~4.0
References The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

*Based on published data.