Brian Ventrudo – Cosmic Pursuits

Roaming the October Skies – A Brief Tour of Aquarius

October 13, 2017 By Brian Ventrudo

The Helix Nebula is a planetary nebula, a cloud of glowing gas ejected by a dying mid-sized star. (Image by Terry Hancock)

Aquarius is a dim constellation in a barren patch of sky far off the plane of the Milky Way. Just east of Capricorn, it marks the 11th constellation of the zodiac. This dim constellation lies near the other “watery” constellations including Cetus, the Sea Monster (or whale), Pisces, the Fishes, and Eridanus, the River. This ancient constellation was associated with water or water bearers since Babylonian times. Some representations have the water bearer pouring water into a stream that leads to the bright star Fomalhaut, the mouth of the southern fishes Piscis Austrinus. Like Capricorn, Aquarius has far fewer deep-sky sights than Sagittarius. But there are a handful of objects here of enduring interest including the famous Helix Nebula, one of the nearest planetary nebulae to Earth. Let’s take a short tour of some of the finer sights in this zodiacal constellation……

Share This:

The Sky This Month – October 2017

September 30, 2017 By Brian Ventrudo

An Orionid meteor, a tiny sliver of Comet Halley, falls into the Earth’s atmosphere in October 2012. Credit: NASA.

If the weather holds, October is a lovely month for stargazing. The Milky Way still lingers in the west along with stars that were prominent in the northern summer. The autumn stars dominate overhead, and the northern winter stars are starting to poke above the eastern horizon. Best of all, you can get in a good night of stargazing without staying up too late. Early this month, there’s a wonderful pairing of planets in the eastern sky before sunrise, two meteor showers, a dramatic occultation of a bright star, another chance to see the ‘False Dawn, and your best chance of the year to see an ‘ice giant’ in the the outer solar system. Here’s what to see in the night sky this month…
…

Share This:

Seeing Carbon Stars, Close Up and Far

September 22, 2017 By Brian Ventrudo

his ALMA image reveals much finer structure in the U Antliae shell than has previously been possible. Around 2700 years ago, U Antliae went through a short period of rapid mass loss. During this period of only a few hundred years, the material making up the shell seen in the new ALMA data was ejected at high speed. Examination of this shell in further detail also shows some evidence of thin, wispy clouds known as filamentary substructures. Credit: ALMA (ESO/NAOJ/NRAO)/F. Kerschbaum

Many experienced stargazers are connoisseurs of carbon stars, deep-red and highly evolved stars that are dredging up carbon and other nuclear reactants from their innards on their way to becoming, briefly, planetary nebulae. These striking stars are the most colorful of all celestial sights and they’ve long intrigued astronomers who are trying to fine tune their theories of how stars come to the end of their lives. Carbon stars are too far away to reveal much detail directly, so astronomers study them indirectly by examining their spectra. But a team of researchers at the remarkable ALMA telescope in northern Chile have captured an amazingly beautiful and revealing image of a carbon star in the constellation Antlia. Let’s have a look at what they saw, then set some time aside to go see a carbon star for ourselves with a small telescope or pair of binoculars…

Share This:

A Stroll Through the Stars of Capricorn

September 15, 2017 By Brian Ventrudo

The globular cluster Messier 30 as captured by the Hubble Space Telescope. Credit: NASA/HST.

Along the path of the zodiac, just east and a little north of Sagittarius, lies the smile-shaped constellation Capricornus. After the gaudy splendors of Sagittarius and other northern summer constellations, Capricornus isn’t much to look at. It’s the smallest constellation of the zodiac and the second-faintest after Cancer. It has just two stars brighter than 4^th magnitude, so it’s a challenge to see this constellation in the city. But Capricornus offers several splendid alignments of stars that make for excellent viewing with a pair of binoculars on nights in August through October. Let’s have a look……

Share This:

The Sky This Month – September 2017

September 1, 2017 By Brian Ventrudo

The eastern sky well after midnight in early September showing the stars of the constellations Perseus and Taurus. Credit: Brian Ventrudo.

The month of September affords stargazers a last chance to see the Milky Way and all its attendant splendors. The rich constellations of Scorpius and Sagittarius are setting for the year, moving a little westward each night, but the lengthening nights keep these stars accessible for a little longer, at least for observers in the northern hemisphere. Southern observers still enjoy the thickest part of the Milky Way almost overhead. In the east, the relatively star-poor constellations of Pegasus, Capricornus, and Piscis Austrinus are moving into view. Observers with very dark sky get the chance this month to see the zodiacal light, a faint wedge of white sunlight reflected from fine dust in the inner solar system. Also this month, low in the southwestern sky at sunset, Jupiter slowly fades from view while Saturn still hangs on, its rings casting dramatic shadows on the disk of the planet. Mercury makes its best showing of the year in the eastern sky before dawn. And the Sun crosses the celestial equator heading south, marking a change of seasons. Here’s what to see in the night sky this month…

4 Sept. Neptune reaches opposition today. This blue-green ice giant, the most distance major planet from the Sun in our solar system, shines at magnitude 7.8 and spans an apparent diameter of 2.4″. Its tiny disk is visible in the constellation Aquarius less than 1º east-southeast of the orange 4th magnitude star Hydor (λ Aquarii). While the planet is plenty bright enough to see with a telescope, or even binoculars, resolving its disk requires some magnification, at least 75x to 100x. The planet’s disk gets larger with more magnification while the images of the stars do not. Visually, the planet has a very pale blue-green color…

Share This:

Field Notes from a First-Time Eclipse Watcher

August 25, 2017 By Brian Ventrudo

A quick snapshot of totality through slightly hazy skies from near Lincoln, Nebraska, on August 21, 2017. Image credit: Brian Ventrudo

“Dad, you finally saw a total solar eclipse. Now you’re a real astronomer”, said my younger daughter in the minutes after the August 21 eclipse.

It was a joke, of course, but I still winced. This was a sore point with me. Forty-five years of stargazing, on and off, and I’d seen thousands of sights in the sky from earthbound satellites to the Moon, from icy flotsam from the outer solar system to the colorful cloud bands of Jupiter, and all manner of wonders of the deep sky including galaxies billions of years older than our solar system. But I’d never seen a total solar eclipse…

Share This:

Touring the Heart of the Milky Way – Part 2

August 18, 2017 By Brian Ventrudo

A look at the deep-sky objects in and around Sagittarius covered in this tour. Objects in white font are covered in this tour. Objects in blue font were covered in the last tour. Click to open in a new tab.

Last week, you began a tour of some of the finer sights in and around the Milky Way in the constellation Sagittarius. This week, let’s look slightly westward to see another handful of splendid sights along the Sagittarius Arm of the Milky Way. The tour follows the objects in the white font in the above image. Those in blue font were covered in last week’s tour.

The base of operations for this tour is the grand constellation Scorpius, the Scorpion. The long, winding constellation is one of the few that obviously resembles its namesake. The claws of the fearsome celestial arachnid face westward towards the relatively sparse star fields of the constellation Libra. At the heart of the scorpion lies the bright red-orange supergiant star Antares. And to the east lies the winding tail that passes through increasingly rich star fields towards the heart of the Milky Way Galaxy…

Share This:

Touring the Heart of the Milky Way – Part 1

August 11, 2017 By Brian Ventrudo

The rich and gauzy star fields along the Milky Way towards the constellations Sagittarius and Scorpius constitute what’s arguably the most beautiful part of the night sky. Northern observers can see these constellations well over the southern horizon in the mid-to-late evening hours in August and September, while southern-hemisphere observers see this glorious region nearly overhead. Aim binoculars or a telescope towards this part of the sky, or simply gaze in this direction on a dark night with your unaided eyes, and you will see something good. The trick is figuring out which sight is which. To help you sort it all out, here’s a step-by-step tour of a small selection of the more prominent sights of the deep sky towards the center of the Milky Way…

Share This:

The Sky This Month – August 2017

August 1, 2017 By Brian Ventrudo

Image of the 2015 total solar eclipse over the Faroe Islands. Credit: David Byrne at Flickr.com

2 August. Look for sand-colored Saturn to the south and west of the waxing gibbous Moon, and north and east of the red-orange star Antares. Well past opposition, the planet is still a dazzling sight in a small telescope all month. Its rings are tilted near maximum, about 27º, the greatest in 15 years, and the planet’s disk is still a respectable 18″ across. If you’ve got a telescope, make some time to see Saturn this month. It’s a beautiful sight…

Share This:

The Mysterious Hiss from the Milky Way

July 22, 2017 By Brian Ventrudo

The northern summer Milky Way. The center of our galaxy lies just above the tree at lower center in this image. The Bell Labs radio engineer Karl Jansky discovered radio emissions from this location in the early 1930s. Image credit: Brian Ventrudo/CosmicPursuits.com.

In the early 1930′s, Bell Labs, the research division of AT&T, launched a project to use radio “short waves” to transmit telephone calls across the Atlantic. The technology to transmit signals via short waves was reasonably well understood. But engineers also needed to understand sources of noise that might interfere with radio communications signals. So the powers-that-were at Bell Labs tasked a young engineer to find sources of radio static that might interfere with transmissions. During his work, this young engineer, Karl Jansky, made an accidental discovery that revolutionized astronomy…

Share This:

Search

Connect