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May 28: Scorpius holds M80
High in the northeast this evening, located within the head of Draco the Dragon, is one of the sky’s most famous and easy-to-split double stars. Nu (ν) Draconis appears to shine as a single 4th-magnitude star to the unaided eye. In truth, it comprises two 5th-magnitude components spaced so widely apart (62”, or a little over an arcminute) that you can spot both in binoculars or even your telescope’s finder scope. They appear nearly identical, each glowing with a soft white light. Both are roughly nine times as bright as the Sun and about 1.7 times as massive as our star. They circle each other every 44,000 years.
Nu1 is the western component, while Nu2 is the eastern star of the pair. According to the late stellar expert Jim Kaler, perhaps the largest difference between them is that Nu2 is itself a double, with a much smaller secondary that orbits the primary in less than 40 days. However, perhaps they aren’t so different after all: Kaler notes that astronomers suspect Nu1 may also be a double, but this has not yet been confirmed.
Sunrise: 5:35 A.M.
Sunset: 8:21 P.M.
Moonrise: 7:17 P.M.
Moonset: 4:04 A.M.
Moon Phase: Waxing gibbous (98%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location.
