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.

Sightseeing Along the Perseus Arm

by Brian Ventrudo Filed Under: Deep Sky

NGC 7635 (the Bubble Nebula) and open star cluster Messier 52 (lower left) in Cassiopeia. This image has a field of view of about 2 degrees on an edge.

As northern autumn turns to winter, the arc of the northern Milky Way reaches nearly overhead in the evening hours. Here we look into the Perseus Arm, the outermost spiral arm of the Milky Way galaxy which is flecked by dozens of sparkling open stars clusters accessible to a small telescope. This region nearly rivals the dense star fields of Scutum and Sagittarius, summer constellations which lie towards the inner arms of the Milky Way. This month, let’s take a quick tour of a few highlights of the Perseus Arm in the constellation Cassiopeia. It’s a perfect part of the sky for visual observing or for taking a few astro-snapshots [Read more…] about Sightseeing Along the Perseus Arm

Share This:
Facebooktwitterredditpinterestlinkedinmail

A Tale of Three Star Clusters

by Brian Ventrudo Filed Under: Deep Sky

The NASA/ESA Hubble Space Telescope has produced this beautiful image of the globular cluster Messier 56 (also known as M 56 or NGC 6779), which is located about 33 000 light years away from the Earth in the constellation of Lyra (The Lyre).

Colder weather moves in this time of year and not a leaf remains on the trees, but the longer nights mean that most of the stars of northern summer still linger. And so I found myself on a clear and chilly night in late October taking in some favorite star clusters along the spine of the Milky Way with a small refractor, while a second small scope and camera took snapshots of the same clusters.

In this month’s tour, let’s look at three of these star clusters, each in spectacular star fields. All come from the Messier list – one tight galactic cluster and two loose globulars. They make for pleasant visual inspection, and all serve as excellent targets for those of you taking snapshots of the sky with a little smart telescope like the Seestar 50 or with your own setup. I captured the live stacked images here with a 72mm refractor and ZWO 676MC camera (in case you were wondering). Each image has the same field of view, about 1 degree on an edge, which gives you a comparative view of these three clusters [Read more…] about A Tale of Three Star Clusters

Share This:
Facebooktwitterredditpinterestlinkedinmail

The Elephant Trunk Nebula

by Brian Ventrudo Filed Under: Deep Sky

The nebula IC 1396, embedded star cluster Trumpler 37, and red supergiant star Mu Cephei (top). The nebula gets its power from the star HD 206267 near the center of this image. The tip of the Elephant Trunk Nebula lies just right 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, a 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:
Facebooktwitterredditpinterestlinkedinmail

Summer Star Clouds

by Brian Ventrudo Filed Under: Deep Sky

At this time of year, just after darkness falls, we get to see the thickest part of the Milky Way extending over more than half the sky from Cygnus to Scutum to Sagittarius. And where there’s Milky Way, there are star clouds. Grab your binoculars or small telescope and take a tour of the best star clouds of a northern summer (and southern winter) with the recent article published in Sky & Telescope magazine. Inspired by the photographic work of E.E. Barnard in the early 20th century, this sky tour starts with the ‘Great Cloud’ of Sagittarius and works northwards, stopping to see many star clusters and dark nebula in and around these regions of shimmering starlight.  It also includes visuals, especially the recent black-and-white film photography of James Cormier. Click on the image to the left to download the article on PDF format (it’s about 6MB). Then enjoy the tour!

Share This:
Facebooktwitterredditpinterestlinkedinmail

Touring the Summer Triangle

by Brian Ventrudo Filed Under: Deep Sky

Long-exposure images of the Summer Triangle (credit: Tien-Chu Chang, Flickr)
Long-exposure image of the Summer Triangle (credit: Tien-Chu Chang/Flickr)

While not a constellation itself, the Summer Triangle dominates the overhead sky in the northern summer and autumn months and guides stargazers to other stars, constellations, and deep-sky sights. The vertices of the triangle are marked by three bright stars Vega, Deneb, and Altair, each of which belong to true constellations Lyra, Cygnus, and Aquila, respectively. The image below shows the Summer Triangle rising as seen from mid-northern latitudes at 10 p.m. in mid July. The triangle is big: it spans about two full hand widths held at arm’s length. The triangle can be seen well south of the equator, too, above the northern horizon. Southern stargazers call it the “Northern Triangle” or the “Winter Triangle” [Read more…] about Touring the Summer Triangle

Share This:
Facebooktwitterredditpinterestlinkedinmail