Deep Sky Observing

Articles about how to understand, find, and see celestial objects including stars, galaxies, nebulae, and star clusters with binoculars, telescopes, and the naked eye.

The Elephant Trunk Nebula

August 25, 2021 by Brian Ventrudo Filed Under: Deep Sky

The nebula IC1396, embedded star cluster Trumpler 37, and red supergiant star Mu Cephei (at extreme right). The nebula gets its power from the star HD206267 near the center of this image. The tip of the Elephant Trunk Nebula lies just below and left of center.

Cepheus, the King, is an ancient and rather dim constellation, but its position along the northern Milky Way means it harbors more than its share of deep-sky sights including star clusters, nebulae, even the lovely Fireworks galaxy (NGC 6946). But the best field of view in the constellation encompasses three deep-sky sights including a star-forming nebula, star cluster, and an aging red supergiant that’s one of the reddest and most luminous stars in the sky [Read more…] about The Elephant Trunk Nebula

Share This:

Runaway Stars

April 30, 2021 by Brian Ventrudo Filed Under: Deep Sky

The runaway star AE Aurigae, above and right of center, embedded in the Flaming Star Nebula (IC 405) in the constellation Auriga.

The Flaming Star Nebula (IC405) ranks as one of the showpiece sights in the northern constellation Auriga. This glowing emission nebula gains its energy from the star AE Aurigae, a 6^th-magnitude massive blue-white star about 1,500 light years away. This brilliant star, which outshines our Sun by some 30,000 times, blasts out ultraviolet light that ionizes the cloud of hydrogen gas around the star. As the hydrogen atoms reassemble, they emit light at signature wavelengths of red and green light that make these nebulae so beautiful. Most such nebulae are energized by stars that formed within their densest and most opaque regions. But that’s not the case with the Flaming Star Nebula. AE Aurigae did not originate here; it’s just passing by chance through a cold cloud of hydrogen as it hurtles through the Milky Way, far removed from the place it was born [Read more…] about Runaway Stars

Share This:

The ‘Intergalactic Wanderer’

March 24, 2021 by Brian Ventrudo Filed Under: Deep Sky

Conjured by Johann Hevelius in the late renaissance, the dim, linear constellation Lynx fills in the space between the much larger constellations Gemini, Auriga, and Ursa Major, just out of the plane of the northern Milky Way. While it doesn’t much resemble its namesake and contains no bright stars, Lynx harbors one of our galaxy’s most distant outliers, the famous ‘Intergalactic Wanderer’ (NGC 2419), a globular cluster that roams the desolate expanse between the Milky Way and the Andromeda Galaxy [Read more…] about The ‘Intergalactic Wanderer’

Share This:

Sightseeing along the Perseus Arm of the Milky Way

February 26, 2021 by Brian Ventrudo Filed Under: Deep Sky

A section of the Perseus Arm of the Milky Way looking overhead from the northern hemisphere in winter.

In the early months of each year, stargazers south of the equator enjoy a dazzling view of a rich part of the Milky Way, one that’s festooned with open star clusters, emission nebulae, and bright blue-white stars. Here, in the constellations Centaurus and Crux, we gaze into one of the two major spiral arms of the Milky Way, the Scutum Centaurus Arm, that originates from the long bar of ancient stars at the core of our galaxy.

An observer looking overhead in the northern hemisphere sees a completely different perspective. Here the view lies in a direction away from the center of the galaxy into the outer reaches of the Perseus Arm, the second major spiral arm that emanates from the galactic core [Read more…] about Sightseeing along the Perseus Arm of the Milky Way

Share This:

The Taurus Molecular Cloud

January 25, 2021 by Brian Ventrudo Filed Under: Deep Sky

Not far from the Pleiades and Hyades star clusters along the northern Milky Way lies the coal-black fingers of the Taurus Molecular Cloud, the nearest star-forming region to Earth. Unlike the more famous Orion star factory, with the dazzling Orion Nebula and associated bright blue-white stars, the TMC is not well known to most stargazers. That’s because it doesn’t offer much to see, with no bright nebulae and just a dark and sooty network of tendrils that span more than 30^o of sky. But the TMC is the nearest star-forming region to Earth, making it of considerable interest to astronomers. It’s also a rewarding target for astrophotographers who can capture its structure against the starry background in the constellations Taurus and Auriga [Read more…] about The Taurus Molecular Cloud

Share This: