July 6
The Thirteenth House
Sun Position
The Sun is in Cancer at roughly +22.5° declination. Northern Hemisphere evenings are long and warm; Southern Hemisphere nights are lengthening past the solstice.
Sky Highlight
The Southern Delta Aquariids meteor shower begins building this week, with activity running from mid-July through late August. The radiant rises from the Southern Hemisphere's eastern sky during the evening hours, making this shower far more productive for southern observers than northern. At its peak around July 29–30 it can reach 20 or more meteors per hour under dark skies in the south.
Deep Sky Object
M10 (NGC 6254), a globular cluster in Ophiuchus roughly 14,300 light-years away. It is a rich, moderately concentrated cluster that resolves into individual stars at the edges in a medium-aperture telescope. Ophiuchus sits on the celestial equator, so M10 is accessible to observers in both hemispheres.
Featured Star
Rasalhague (α Oph) is a white giant about 47 light-years away in Ophiuchus, classified A5III. Ophiuchus, the Serpent Bearer, straddles the ecliptic and the Sun passes through it each November, making Rasalhague the brightest star of what is sometimes called the zodiac's unofficial thirteenth constellation.
Around This Date
- July 6, 1957The International Geophysical Year began, an 18-month global scientific cooperation effort that included the first successful satellite launches by both the United States and the Soviet Union.
- July 9, 1979Voyager 2 made its closest approach to Jupiter, returning detailed images of the Great Red Spot and discovering active volcanoes on the moon Io, already confirmed by Voyager 1 months earlier.
Rasalhague keeps watch over a constellation that the Sun visits every November, unhurried by the zodiac's reluctance to count to thirteen.