July 2
The Sting in the Tail
Sun Position
The Sun is in Cancer, near the +23° declination band. Northern Hemisphere days remain at their longest; in the Southern Hemisphere midwinter has settled in, with long nights well suited to deep-sky observing.
Sky Highlight
The Scorpiids-Sagittarids meteor shower, a minor but broad activity window, is active through early July. Rates are low (typically a few per hour) but the radiant lies in the rich Milky Way field near Scorpius and Sagittarius, so stray meteors against a dark background can be rewarding. Best from the Southern Hemisphere and southern northern latitudes where the radiant clears the horizon.
Deep Sky Object
M6 (NGC 6405), the Butterfly Cluster, an open cluster in Scorpius roughly 1,600 light-years away. Its brightest star, BM Scorpii, is an orange supergiant that stands out warmly against the cluster's hotter blue-white members, giving the group a subtly varied color palette. Southern Hemisphere observers see it well overhead; northern observers below about 40°N can catch it low in the south.
Featured Star
Shaula (λ Sco) is a triple star system about 700 light-years away in Scorpius, with a blue subgiant primary classified B1.5IV, a hot, massive star near the end of its main-sequence life. It marks the scorpion's sting at the tip of the curved tail and ranks among the twenty brightest stars in the sky.
Around This Date
- July 2, 1900Max Planck submitted a short note to the German Physical Society proposing that electromagnetic energy is emitted in discrete quanta, work that directly underpins our understanding of stellar spectra and blackbody radiation.
- July 4, 1054The supernova recorded by Chinese court astronomers in Taurus on this date produced what is now the Crab Nebula, a remnant whose pulsar still pulses 30 times per second.
Seven hundred light-years of travel, and Shaula still arrives as a sharp white point at the scorpion's tip.