Cosmic Pursuits

Basic astronomy and night sky information

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 Eta Carinae Nebula

by Brian Ventrudo Filed Under: Astronomy Images and Video, Deep Sky

The Eta Carinae Nebula, just above center, seen in this wide nightscape image of the southern Milky Way in 2023 from the Rio Hurtado region of northern Chile. Image credit: Brian Ventrudo

The Eta Carinae Nebula, the jewel of the southern-hemisphere constellation Carina, the Keel, is the most spectacular example of an active star factory in all the heavens. The nebula is about 260 light years across, some seven times larger than the Orion Nebula. And while 7,500 light years away, five times farther away than Orion, it’s still easily visible to the even the most casual stargazer as a large frosty patch three times as wide as the full Moon in the Milky Way west of the constellation Crux, the Southern Cross [Read more…] about The Eta Carinae Nebula

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Touring Queen Berenice’s Hair

by Brian Ventrudo Filed Under: Deep Sky

An historical representation of the constellations Bootes, Canes Venatici, and Coma Berenices (lower right).

Let’s take a look at the ancient constellation Coma Berenices, a faint group of stars tucked under the handle of the Dipper halfway between the stars Arcturus and Denebola in Leo’s hindquarters. There is something for everyone here: history and legend, a beautiful naked-eye star cluster that invites careful inspection, and dozens of galaxies to explore with a modest telescope. And armchair astronomers can contemplate the immensely distant Coma Cluster of Galaxies, some 300 million light years away, that first yielded evidence for the mysterious dark matter that makes up a good portion of the universe [Read more…] about Touring Queen Berenice’s Hair

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The Sound of the Jellyfish Nebula

by Brian Ventrudo Filed Under: Deep Sky, Science

A composite false-color image of the Jellyfish Nebula (IC443). Red indicates visible light, green shows regions of radio emission, and blue shows X-ray emission. Image credit: NASA/Chandra X-Ray Observatory.

Not far from the bright star Propus in the feet of the constellation Gemini lies the supernova remnant IC443,  also known as Sharpless 248, but which is more evocatively known as the Jellyfish Nebula. While it’s a difficult object to see visually, this cosmic echo of a long-dead star presents a superb target for imagers because of its turbulent and complex structure. The nebula, which is about 5,000 light years away, is adjacent to a rich region of new star formation called Sharpless 249 in the Orion Spur of the Milky Way which makes the whole region even more photogenic.

The Jellyfish Nebula got its start when a massive star ran out of fuel, quickly collapsed, and detonated as a supernova about 30,000 years ago in a gas-strewn patch of the Milky Way. The shock wave from the explosion collided with clouds of interstellar gas and set them aglow to produced the intricate lacework of nebulosity that makes up the nebula. Most of the glowing gas is hydrogen, but there are also traces of light from ionized oxygen, sulfur, and other elements.
[Read more…] about The Sound of the Jellyfish Nebula

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The Flaming Star Nebula

by Brian Ventrudo Filed Under: Deep Sky

The runaway star AE Aurigae, the bright star below center, embedded in the Flaming Star Nebula (IC 405) in the constellation Auriga. This image spans about 2 degrees on each edge.

The Flaming Star Nebula (IC 405 or Caldwell 31) makes the must-see lists of many visual stargazers and astronomical imagers this time of year. This showpiece nebula in the northern constellation Auriga gains its energy from the star AE Aurigae, a 6th-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 visible wavelengths that make these nebulae so beautiful. IC 405 features a remarkably complex structure with knots of glowing gas that do indeed resemble starry flames frozen into the dark background sky.
[Read more…] about The Flaming Star Nebula

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Star Factories in Cepheus

by Brian Ventrudo Filed Under: Deep Sky

A deep-field H-alpha image of a small region in Cepheus, about 7 degrees on each edge, showing the nebula IC 1396 surrounding the star cluster Trumpler 37 at lower right and the ‘Flying Bat’ nebula, Sh2-129, at the upper left of the image.

This month we turn our gaze to a field of view about 7o square in the crooked-house of the constellation Cepheus. The field is a little smaller than your closed fist held at arm’s length. In the image above, captured in H-alpha with a small monochrome astronomy camera and a 90 mm lens, you see in this field a pair of spectacular emission nebulae, an embedded star cluster, half-dozen dark nebulae hiding regions of new star formation, and a blazing late-stage star on the verge of blowing itself to bits. [Read more…] about Star Factories in Cepheus

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