July 19
The Oblong Eagle
Sun Position
The Sun is in Cancer at about +20.3° declination. Northern Hemisphere summer; Southern Hemisphere winter. Aquila is rising well in the east after dark from both hemispheres.
Sky Highlight
No named meteor shower peaks on July 19. Aquila and the Summer Triangle are dominant in the eastern evening sky across the Northern Hemisphere. From Australia and southern South America, the Summer Triangle is better called the 'Winter Triangle' and rises in the northeast, with Altair the first and brightest of the three to clear the horizon.
Deep Sky Object
NGC 6751, the Glowing Eye Nebula, a planetary nebula in Aquila roughly 6,500 light-years away. It has a roughly circular shell surrounding a very hot central star, with a bluish tint visible in photographs. A small-to-medium telescope shows a faint disk; detailed structure requires larger aperture. Visible from both hemispheres.
Featured Star
Altair (α Aql) is only 16.73 light-years away, one of the twenty nearest stars to the Sun. Its A7V classification places it slightly cooler than Vega but still a hot white star; its extraordinary spin rate (about 286 km/s at the equator) has been directly imaged using optical interferometry, showing a disk noticeably flattened at the poles.
Around This Date
- July 19, 1950The first launch attempt from Cape Canaveral took place, a Bumper V-2/WAC Corporal two-stage rocket that aborted on the pad when the main chamber failed to ignite, marking the opening of what would become the world's most active launch site.
- July 20, 1944The experimental MW 18014 V-2 rocket reached an altitude of 176 km during a test flight, crossing the boundary of space and becoming the first man-made object to do so.
Altair spins so fast its own shape betrays it, not quite round, just close enough to trick the eye.