Cosmic Pursuits

Basic astronomy and night sky information

veil nebula

Nebula Hopping in the Constellation Cygnus

by Brian Ventrudo Filed Under: Deep Sky

The North America Nebula (on its side) and above it the Pelican Nebula in the constellation Cygnus.

Like many constellations along the arc of the Milky Way, the constellation Cygnus harbors an embarrassment of celestial riches. There’s everything here: emission nebula, supernova remnants, open star clusters, star clouds, and dark nebulae that reach like intertwined fingers over the bright and unresolved star clouds in this part of the sky. In dark sky, with a pair of binoculars or wide-field telescope, a contemplative stargazer can spend many happy hours hopping from object to object, wondering why more people turn their eyes skyward more often.

Which is what I was doing on a cool northern autumn night as I toured the celestial Swan, looking for a handful of pretty emission nebulae that radiate a deep red light and stand out along the rich star field in this part of the sky. These nebulae make ideal targets for urban stargazers like me because their contrast is readily enhanced with a good light pollution filter which passes their emission while reducing the effect of urban light pollution. The nebula doesn’t appear brighter, but it does have better contrast against fish-grey urban and suburban skies [Read more…] about Nebula Hopping in the Constellation Cygnus

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The Veil Nebula

by Brian Ventrudo Filed Under: Deep Sky

The Veil Nebula in the constellation Cygnus. The right section (NGC 6960) overlaps with the star 52 Cygni. The brighter arc at left is NGC 6992. In between lies Pickering’s Triangle. Click image to enlarge in a new window. Image credit: Brian Ventrudo/Cosmic Pursuits.

“It’s better to burn out than to fade away”, as Neil Young once said, and when it comes to burning out nothing beats a big star that blows up as a supernova. These catastrophic events occur as big stars run out of fuel in their core and become unable to hold themselves up against the relentless pull of their own gravity. Their outer layers collapse, crush the star’s dense core into a neutron star or black hole, then snap back in a violent explosion that eject as much energy in a few minutes as our sun does in its entire lifetime.

Since only the largest stars expire like this, and since the explosion itself plays out quickly over a few days or weeks, a supernova is a relatively rare event: the last known supernova in the Milky Way happened more than 400 years ago. But such explosions often leave a long-lasting imprint in the form of a visible nebula caused by the rapidly expanding shock wave of the exploding star colliding with and setting aglow the rarefied gas of the interstellar medium. Dozens of these so-called supernova remnants fleck the night sky. Most require a big telescope and sensitive camera to detect, but one of the brightest and easiest to see lies off the eastern ‘wing’ of the constellation Cygnus, the Swan. This is the famous Veil Nebula, a sprawling complex of glowing gas and one of the most intricate and intrinsically beautiful objects in our galaxy [Read more…] about The Veil Nebula

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Deep Sky Tour: Nebulae in Cygnus

by Joe Bergeron Filed Under: Deep Sky

The North America Nebula (left) and the Pelican Nebula (right). Image credit: Terry Hancock via Flickr.

In my previous sky tour, I talked up the virtues of observing deep sky objects using fairly high magnifications with a reasonably big 8-inch f/10 telescope. This time around, let’s veer to the opposite extreme and take a tour of a series of celestial objects that are best seen using small telescopes, low magnifications, and wide fields of view.

Cygnus, the Swan, which is as emblematic of northern-hemisphere summer as any other constellation, holds two of the best examples of wide-field objects which are visible nearly overhead in late northern summer, and low over the northern horizon for southern-hemisphere observers [Read more…] about Deep Sky Tour: Nebulae in Cygnus

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Simulating a Supernova in an Aquarium

by Brian Ventrudo Filed Under: Science

NOVAE – An aesthetic vision of a supernova from Thomas Vanz on Vimeo.

Astronomers have a reasonably good handle on what happens during a supernova, an immense stellar detonation that occurs when a massive star that’s run out of fuel collapses and explodes with the brightness of 10 billion suns . These events are relatively rare, with just one or two each year, on average, in a galaxy the size of our Milky Way. While the math and physics of a supernova explosion are reasonably well understood, it’s up to visual artists and computer-generated imagery (CGI) experts to help us visualize a supernova explosion in all its glorious violence and complexity [Read more…] about Simulating a Supernova in an Aquarium

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