June 10
The Dragon's Eye
Sun Position
The Sun is in Gemini, declination near +23°. The Northern Hemisphere's longest days are almost here; Draco curves high overhead in the north.
Sky Highlight
An annular solar eclipse can occur near this calendar date in some years (notably June 10, 2021), when the Moon is near apogee and leaves a ring of sunlight visible from a narrow path. No eclipse falls on most June 10ths, but the date is a reminder that solar geometry can produce the 'ring of fire' effect.
Deep Sky Object
NGC 6543 (Cat's Eye Nebula), a planetary nebula roughly 3,300 light-years away. The Cat's Eye Nebula in Draco shows concentric shells of gas expelled by a dying sun-like star, with a structure so complex it suggests episodic mass loss rather than a single ejection event. Circumpolar from mid-northern latitudes; highest in the sky in June evenings, though its small angular size requires a telescope.
Featured Star
Etamin (γ Dra) is an orange giant (K5III) about 148 light-years away, the brightest star in Draco; it served as a pole star around 3,000 years ago and, in 1728, its apparent shift in position as Earth orbited the Sun allowed James Bradley to discover the aberration of starlight, the first direct observational evidence that Earth moves. The dragon's eye has a history it doesn't advertise.
Around This Date
- June 10, 2021An annular solar eclipse crossed northeastern North America and Greenland, with the ring-of-fire effect visible along a narrow path through Ontario, Quebec, and the Arctic.
- June 10, 2003NASA launched the Spirit rover toward Mars on a Delta II rocket, beginning the Mars Exploration Rover mission; Spirit landed in Gusev Crater in January 2004 and operated for over six years before becoming immobile in soft soil.
This star taught us the Earth moves, not through any star's motion, but through our own.