Brian Ventrudo

A Quintuple Star in the Constellation Orion

January 25, 2019 by Brian Ventrudo Filed Under: Deep Sky

The complex of emission, reflection, and dark nebulae near the star Alnitak and Sigma Orionis. The Horsehead Nebula is at center. Sigma Orionis is the bright star to the left of the Horsehead. The pale white Flame Nebula, split in two by a dark lane of dust, is at bottom and just right of center. Image credit: Terry Hancock and GrandMesaObservatory.com

Perhaps the finest multiple star in the sky visible to both northern and southern observers, Sigma Orionis is a gravitationally-bound system of five stars, four of which are visible upon careful inspection with a small telescope. The brightest star of this group is one of the most luminous known, and it lights up the gas and dust around the famous Horsehead Nebula near Orion’s Belt. The star will one day expire, like many stars in Orion, in a spectacular supernova explosion.

Sigma Orionis doesn’t have an easy-to-remember name, but it’s not hard to find. It’s just south of Alnitak, the easternmost star in Orion’s Belt. The total visual magnitude is 3.6, so it’s visible even in light-polluted city skies [Read more…] about A Quintuple Star in the Constellation Orion

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The ‘Seven (Dusty) Sisters’

January 18, 2019 by Brian Ventrudo Filed Under: Deep Sky

An image of the Pleiades Star Cluster (Messier 45) and surrounding region. Image courtesy of Terry Hancock and Grand Mesa Observatory.

Like many observers both casual and serious, I do not tire of gazing upon the little star cluster known as the Pleiades. I’ve seen the cluster a thousand times, but I’ll still stop and take a long look at it without optics while out for a walk on a winter’s night. Some night I’ll grab a pair of binoculars and make a closer inspection of the cluster, which fits perfectly in the field of view of such an instrument. And if it’s not too cold, I’ll pull out a telescope and a wide-field eyepiece and spend 20 minutes taking in the astonishing view of this group of blue-white stars that formed while dinosaurs still roamed the Earth. Which, in celestial terms, was not all that long ago.

Why keep looking at the Pleiades after so many years? The cluster doesn’t appear to change, of course, in the restricted timescale of a human life. But the Pleiades is a profoundly beautiful sight, as pleasing as a field of alpine wildflowers, and I never fail to see new patterns of stars both bright and dim that I hadn’t noticed before [Read more…] about The ‘Seven (Dusty) Sisters’

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The Golden Light of a Winter Solstice

December 21, 2018 by Brian Ventrudo Filed Under: Astronomy Images and Video

“What good is the warmth of summer, without the cold of winter to give it sweetness.”
― John Steinbeck

On December 21, 2018 at 22:23 Universal Time, the Sun reaches the December solstice, its most southern point on the ecliptic. This marks the first day of winter in the northern hemisphere and the first day of summer in the southern hemisphere [Read more…] about The Golden Light of a Winter Solstice

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The Christmas Comet of 2018

December 14, 2018 by Brian Ventrudo Filed Under: Celestial Events

Comet 45/P Wirtanen on December 9, 2018 through a telescope. Image courtesy of Transient Astronomer and Grand Mesa Observatory.

The year 2018 winds down with the apparition of the modest but easily observable Comet 46/P (Wirtanen). This periodic comet will not rival some of the better “Comets of Christmas Past” such as Comet McNaught in 2006, Comet Hale-Bopp as it brightened towards the end of 1996, or even the relatively disappointing Comet Kohoutek in 1973. But Comet Wirtanen will grow bright enough to see with binoculars and, in dark sky, with the naked eye as it passes through some of the most prominent constellations of the season. It’s a great excuse to dust off your optics and get outside to enjoy the solar system in action and share the view with those around you [Read more…] about The Christmas Comet of 2018

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The Lonely Star of Autumn

December 7, 2018 by Brian Ventrudo Filed Under: Deep Sky

This illustration shows a ring of debris encircling the star Fomalhaut. A suspected planet is orbiting inside the ring. Credit: NASA, ESA and A. Feild (STScI)

In the vast expanse of sky between the brilliant stars Antares in the west and Sirius in the east, there lies but a single bright star of note, the star Fomalhaut. Low and prominent over the southern horizon, this lovely white star is a lonely sight on a northern fall evening. Fomalhaut marks the mouth of the constellation Piscis Austrinus (the Southern Fish). The star is a pretty enough sight for casual stargazers this time of year, and it offers a very widely spaced companion that’s easy to see in binoculars. The star also hosts at least one ring of glowing dust and debris left over from its birth. And where there’s dust, there may very well be planets… [Read more…] about The Lonely Star of Autumn

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