Tails in the Sky

Fred Schaaf in his Sky & Telescope column for this month looks back fondly on the great comet tails that graced the May sky 33 and 30 years ago – Iras-Araki-Alcock and Halley – and then points out that the tails of several constellation animals are arrayed along the meridian of the May evening sky.  So I thought I’d show them.

In the north are the curves of stars that mark the tails of Ursa Minor and Ursa Major, the Little Bear and the Great Bear (though bears don’t really have tails); between swishes the long tail of Draco the Dragon; Leo’s tail, now docked, once reached to a tuft that is now Coma, the Hair of Berenice; and across the south floats the longest of all tails, that of Hydra the Water-Snake.  Cygnus the Swan, dominated by Deneb the star whose name means “tail,” has risen in the northeast; of Serpens, the snake held by Ophiuchus, it is unfortunately Caput, the head, that rises first and so Cauda the tail is only just coming into view; and the tail of Scorpius, the notable part he whips over his head to sting you with, is below the horizon.  Virgo, though sitting on the meridian, doesn’t really have a tail unless she’s a Mer-Maiden.

Creatures distributed in many other parts of the sky – fishes, dogs, birds, the Whale, Lizard, Fox, Wolf – must have tails; Delphinus also has a tail star named Deneb; there are single stars that we can call the tails of Canis Major and Minor; and Fred mentions Canes Venatici, the Hunting Dogs.  But great tails, pictured in curving lines of stars, do happen to be draped across this arching meridian of about 12 hours sidereal time.

(I can’t give a link to Fred’s article alone, only to the digital version of the whole issue in which it’s on page 45: http://www.shopatsky.com/sky-and-telescope-may-2016-digital-issue – let me know if this works.

( P.S.: I now realize it doesn’t, unless you subscribe to S&T.  Sorry.  Perhaps another time I’ll give a scanned picture of an article.)