July 16
The Herdsman's Uncertain Star
Sun Position
The Sun enters Leo on approximately July 22โ23; on July 16 it is still in Cancer at about +21.3ยฐ declination. Long northern days; Southern Hemisphere winter.
Sky Highlight
No major annual sky event peaks on July 16. Boรถtes is setting in the western sky by midnight, making July evenings the last good window for observing Seginus and other Boรถtes stars in the Northern Hemisphere before they follow the spring constellations into the western twilight. Southern Hemisphere observers see Boรถtes low in the northwest.
Deep Sky Object
NGC 5466, a globular cluster in Boรถtes roughly 51,800 light-years away. It is a loose, low-concentration cluster and one of the most distant globulars routinely observed by amateur astronomers; its stars are sparsely packed and it appears as a faint haze in small telescopes. Best from the Northern Hemisphere.
Featured Star
Seginus (ฮณ Boo) is a white giant about 85 light-years away in Boรถtes, classified A7III. Its name has been traced to various Arabic and Latin roots, but modern scholars have found no clear original meaning, it may be a transcription error from early star catalogues. The star itself is unremarkable by comparison to Boรถtes's showpieces, but its uncertain name gives it a quiet footnote in the history of stellar nomenclature.
Around This Date
- July 16, 1969Apollo 11 launched from Cape Kennedy at 9:32 a.m. EDT, beginning the first crewed mission to land humans on the Moon.
- July 16, 1994Comet Shoemaker-Levy 9 Fragment A struck Jupiter, beginning a week of impacts that were the first directly observed collision of solar system bodies.
Seginus has a name nobody can fully trace, sometimes that is the most interesting thing about a star.