Cosmic Pursuits

Basic astronomy and night sky information

Recent Astronomy Articles at Cosmic Pursuits

Chandra’s Limit

by Brian Ventrudo Filed Under: Uncategorized

Thursday, April 23, 2015​

1. Chandra’s Limit

In which your publisher recounts his youthful brush with astrophysical greatness, and attempts to explain why there are no fat white dwarf stars in the universe. (Yes, the two topics are related… sort of).

2. Mercury Appears… and Gets Smacked!

Just as the planet Venus skimmed the Pleiades star cluster after sunset a few weeks ago, the tiny planet Mercury does the same this week on April 30, 2015. You can see planet and star cluster low in the northwestern sky just after sunset. And remarkably, on the same day, NASA’s MESSENGER spacecraft ends its mission by slamming into Mercury at 8,000 mph. It’s a big day for the little planet!

3. Messier 13 Returns

As a chronic insomniac, I often wander out late at night to see what’s coming over the eastern horizon (fact: you can tell how little sleep I’ve had by the average number of typos in these emails). Anyway, I noticed mighty Hercules wheeling into view last week, which brought me thoughts of my favorite summer stars. This short piece on M13 will help get you in the mood for stargazing, and it features a fine image from a young stargazer living in the washed out skies of London, U.K.

4. A Conspiracy of None

The final article on the ‘retired’ One-Minute Astronomer site tells of the return of the mysterious ‘white spots’ on the dwarf planet Ceres. The spots returned to view this week as the Dawn spacecraft maneuvered into a different orbit to take a look at the lighted side of this small world. The conspiracy theorists have been silenced… for now.

+ Extras

Finally, for you astronomical art collectors out there, my friend Terry Hancock is offering for auction on eBay a signed one-of-a-kind aluminum print of his magnificent image of Orion ‘Clouds of Creation’. The print is 40″x95″ on an aluminum base that has the gleam of a new car finish. ideal for the rich detail in this panorama. The image on this museum-grade print was made from 420 individual exposures. See the auction at this link…

Wishing you clear skies,

Brian Ventrudo
Publisher, Cosmic Pursuits
CosmicPursuits.com

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New Image of Pluto and Charon from ‘New Horizons’

by Brian Ventrudo Filed Under: Solar System

3-opnav3_plutcen_noano-1041_0Just 11 weeks left to go until the closest flyby of New Horizons by Pluto. These images, released on April 29, 2015, show Pluto and its largest moon Charon, which is as large as Texas, revolving about their common center of mass. You can also see Pluto rotating about its own axis, ‘like a chicken on a BBQ spit’. Most amazingly, there are surface features visible on the surface of Pluto including a bright patch at one of the poles. NASA explained that these surface markings are remarkably visible compared to other planets given the distance and size of Pluto. These constitute the most detailed images ever captured of the ‘former planet’. The view will only get better from here.

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See the Eta Aquariid Meteor Shower

by Brian Ventrudo Filed Under: Solar System

An Eta Aquariid meteor over the Devil's Tower in Wyoming (credit: David Kingham)
An Eta Aquariid meteor over the Devil’s Tower in Wyoming (credit: David Kingham)

The usually reliable Eta Aquarid meteor shower peaks on the night of May 5-6 this year. The shower runs from April 21 – May 20, 2015, with many meteors still visible for several days on either side of the peak. It is perhaps the best meteor shower of the year for southern hemisphere stargazers.

The annual Eta Aquarids occur as Earth passes through an stream of icy and dusty debris from the famous Comet 1/P Halley, more commonly called Halley’s Comet. We pass through a second stream of the comet in late October. This results in the Orionid meteor shower. So if you missed the comet during its last apparition in 1986, you can at least see sand-grain-sized bits of the comet burn up in the atmosphere during these two meteor showers.

The Eta Aquarids gets its name from the 4th magnitude star Eta Aquarii in the constellation Aquarius. The star is 168 light years away and bears no physical relation to the meteor shower. But the meteors appear to trace their paths back to a point in the sky near this star as the Earth moves into the debris field.

Because Aquarius lies on the ecliptic well south of the celestial equator, this is a better meteor shower for observers in the southern hemisphere. Rates of 30-60 meteors per hour are typical. Northern stargazers can see perhaps half as many near peak, but it’s still an impressive event. The Eta Aquarids on average are quite speedy and enter the atmosphere at 66 km/s (148,000 mph).

As with most meteor showers, the hours before twilight dawn, as the Earth turns into the meteor stream, are the best time to see the Eta Aquarids. You don’t need to find the star Eta Aquarii to see the meteors. They can appear anywhere in the sky. You don’t need any optics… just lie back under dark sky and look up.

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Jupiter Shadow Transit with an iPhone

by Brian Ventrudo Filed Under: Astronomy Images and Video, Solar System

Enjoy this short four-image GIF of the transit of the shadow of Ganymede across the face of Jupiter on April 14, 2015. Taken by Andrew Symes of Ottawa, Canada with an iPhone 6 and a Celestron NexStar 8SE alt-az telescope, this image also shows several belts and zones in the atmosphere of Jupiter including the prominent north and south equatorial belts, along with the possibly perpetual anticyclone of the Great Red Spot.

 

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Messier 13 Returns

by Brian Ventrudo Filed Under: Deep Sky

Like an old friend returning after a long absence, the dazzling globular cluster Messier 13 in the constellation Hercules rises in the eastern sky a little earlier each night, a welcome sight along with the bright stars constellations of northern spring and summer.

Location of M13 in the Keystone of Hercules. Click to enlarge. (image created with SkySafari4)

M13 is one of the finest showpieces of the northern spring and summer skies. It’s located along one edge of the “Keystone” shape of Hercules (see image below). Just at the limit of human eyesight, M13 holds a million stars some 12-13 billion years old, nearly as old as the universe [Read more…] about Messier 13 Returns

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