Vulpecula

Features

No stars in Vulpecula are brighter than 4th magnitude. This star is an optical binary with a separation of 413.7 arcseconds, splittable with binoculars, and carries the traditional name Anser, referring to the goose the little fox holds in its jaws. The second-brightest star is 23 Vulpeculae. In 1967, the first pulsar, PSR B1919+21, was discovered in Vulpecula by Jocelyn Bell, supervised by Antony Hewish, while they searched for scintillation of radio signals from quasars.

They observed pulses repeating every 1.3373 seconds; terrestrial origin was ruled out because the object reappeared after a sidereal day rather than a solar day, and the signal was identified as coming from a rapidly rotating neutron star. Fifteen years later, the first millisecond pulsar, PSR B1937+21, was also discovered in Vulpecula, only a few degrees away. The constellation hosts HD 189733 b, one of the closest extrasolar planets studied by the Spitzer Space Telescope; in 2007, a team led by Giovanna Tinetti published evidence for significant water vapor in its atmosphere, though its temperatures exceed 1,000 °C. Also located here is soft gamma repeater SGR 1935+2154, which emitted a fast radio burst in 2020, the first observed in the Milky Way.

The Dumbbell Nebula (M27) is a large, bright planetary nebula discovered by Charles Messier in 1764 as the first object of its kind. It appears as a dimly glowing disk about 8 arcminutes in diameter with binoculars in a dark sky, is roughly 9,800 years old, and a telescope reveals its double-lobed hourglass shape. Brocchi's Cluster (Collinder 399), also called the Coathanger, is an asterism formerly thought to be an open cluster.