June 28
Bear's Guardian
Sun Position
The Sun is in Cancer, declination near +23.1°. Northern days are shortening, though midsummer warmth peaks now or soon; evenings are comfortable and dark skies arrive later.
Sky Highlight
No major meteor shower peaks today. Boötes and Arcturus are ideally placed at this time of year. Arcturus transits high in the south at nightfall for northern observers, making early summer the best season to study the herdsman constellation.
Deep Sky Object
NGC 5466, a globular cluster about 51,800 light-years away. NGC 5466 in Boötes is notable for its visible tidal stellar stream (a ribbon of stars stripped by the Milky Way's gravity) and is one of the most diffuse globular clusters known, with an unusually low central density. Well-placed in June evenings from northern latitudes; requires a mid-sized telescope to see well.
Featured Star
Arcturus (α Boo) is a red giant (K1.5IIIFe-0.5) just 37 light-years away, the brightest star in the northern sky and one of the closest giant stars to Earth; it is moving rapidly relative to the galactic disk, a visitor from the Milky Way's thick disk on a different orbital path than most neighboring stars. Its name, from Greek, means 'guardian of the bear.'
Around This Date
- June 27, 1995Space Shuttle Atlantis docked with the Mir space station on the STS-71 mission, the first time a Shuttle had docked with Mir.
- June 28, 1911The Nakhla meteorite fell in Egypt near Alexandria, later identified as a fragment of Mars and one of the first meteorites to show evidence of aqueous alteration, suggesting that liquid water once flowed on the Martian surface.
The brightest star in the northern sky is a visitor on a different orbital track, passing through the neighborhood on its own schedule.