The Coathanger or Brocchi’s cluster is a tiny asterism – a pattern of stars that is not a constellation. This star formation looks exactly like its namesake, and is amazingly easy to make out through binoculars. The whole trick to viewing the Coathanger is to know just where to look.
Fortunately, the famous Summer Triangle asterism can help point the way. The Milky Way – the edgewise view into the flat disk of our galaxy – runs right through this asterism, so there are many cool little clusters here, plus, of course, the great and glorious Dark Rift of the Milky Way. If you can find the Summer Triangle, you can find the Coathanger, especially if you’re looking from a rural location, and have some binoculars handy. The cluster is located along a line between two Triangle stars, Vega and Altair. The photo below illustrates the view.
Here’s another way to find the Coathanger, but it requires that you find a slightly fainter star, beloved Albireo – located in the midst of the Summer Triangle – also seen as the bottom of a second asterism called the Northern Cross. The entire Northern Cross asterism lies inside the Summer Triangle.
Albireo is found at the base of the Northern Cross.
Got Albireo? Now for some specifics on finding the Coathanger. With binoculars, look for the brightest star in the vicinity of Albireo. That star is called Alpha Vulpeculae, which appears as a double star through binoculars (though the two stars are not gravitationally bound).
Draw an imaginary line from Albireo through Alpha Vulpeculae to locate the Coathanger. In most binoculars, Alpha Vulpeculae and the Coathanger fit within the same binocular field of view, though just barely.
Notice that six stars form the bar of the Coathanger, while four stars make up the hook. From mid-northern latitudes, the Coathanger often appears upside-down. That’s why some people call it the Ski Lift.
Hint: The Coathanger is tiny. If you keep getting lost while using your binoculars, place the bottom of the view at the top of a tree (or building), then go from your landmark upward until you catch sight of the object.
When should you look? Our sky chart above shows the stars as they appear from the Northern Hemisphere in middle July around midnight (1 a.m. daylight saving time).
Because the stars return to the same place in the sky some two hours earlier with each passing month, this sky chart also shows star positions for about 10 p.m. (11 p.m. daylight saving time) in mid-August, 8 p.m. (9 p.m. daylight saving time) in mid-September and 6 p.m (7 p.m daylight saving time) in mid-October.
Since these stars shine from south to overhead at these times (as seen from the Northern Hemisphere), you might want to sprawl out on a reclining lawn chair, with your feet pointing southward. A reclining position saves neck strain.
Incidentally, the Coathanger – aka Brocchi’s cluster – isn’t a true cluster, but a chance alignment of physically unrelated stars.
The Coathanger’s position is at RA: 19h 26.47′; Dec: 20o 11.93′
Bottom line: Star-hop to the Coathanger – a tiny asterism that really looks like its namesake – via the stars Albireo and Alpha Vulpeculae.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.