July 5
The Future Pole Star
Sun Position
The Sun is in Cancer at about +22.7° declination. Northern Hemisphere days are long and bright; Southern Hemisphere observers are in deep winter with extended dark skies.
Sky Highlight
The Capricornids meteor shower begins its activity period around July 5, building slowly toward a broad peak around July 25–30. Rates are modest (typically 5 to 10 per hour at maximum) but the shower sometimes produces bright, slow, yellow-orange fireballs. The radiant is in Capricornus, making the shower best seen from equatorial and Southern Hemisphere locations.
Deep Sky Object
M57 (NGC 6720), the Ring Nebula, a planetary nebula in Lyra roughly 2,300 light-years away. It appears as a tiny, distinct smoke ring in even a modest telescope and represents the shed outer layers of a dying star similar to the Sun. Well-placed overhead in Northern Hemisphere summer evenings; also visible from southern mid-latitudes.
Featured Star
Vega (α Lyr) is a main-sequence A-type star just 25.04 light-years away in Lyra, classified A0Va, one of the nearest bright stars and the second-brightest in the northern sky. Earth's precession will bring the north celestial pole within about 5° of Vega around the year 13,727, making it a future pole star roughly 12,000 years from now.
Around This Date
- July 5, 1687Isaac Newton's Principia Mathematica was officially published by Edmond Halley, laying out the law of universal gravitation and the mathematics underlying all subsequent orbital mechanics.
- July 6, 1054Arab and Chinese records from this week in 1054 CE describe the new 'guest star' in Taurus as visible in daylight, the supernova event confirmed by modern pulsar timing in the Crab Nebula remnant.
Vega is close enough that the light you see tonight left during a human lifetime, yet it is already rehearsing for its role as pole star twelve thousand years hence.