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Brian Ventrudo

The Cat’s Eye Nebula

November 8, 2018 by Brian Ventrudo Filed Under: Deep Sky

An image of the Cat’s Eye Nebula captured with the Hubble Space Telescope. Image credit: NASA.

Unlike galaxies and star clusters and even emission nebulae, the class of objects known as planetary nebulae exist on a scale of space and time that’s comprehensible, relevant, and compelling to most humans.

Comprehensible because these tenuous exhalations of dying stars are roughly the size of a solar system, which means light can pass from one end of the nebula to the other in just a few hours, and even our current spacecraft could cross some of these nebulae in a matter of years.

Relevant because our own Sun will expire after creating its own planetary nebula in a few billion years when our star’s inner core boils off its outer layers in an intermittent nuclear frenzy.

And compelling because as you observe these objects with your telescope, you may be witnessing the death of other solar systems which once harbored intelligent civilizations that long ago passed into oblivion, or perhaps learned to travel elsewhere in the galaxy before it was too late. Amateur astronomy is, after all, a pastime of the imagination [Read more…] about The Cat’s Eye Nebula

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Filed Under: Deep Sky

A Trek Through Triangulum

October 25, 2018 by Brian Ventrudo Filed Under: Stargazing

The small constellation Triangulum wedged between Andromeda and Aries.

Take any three stars and they’ll form some kind of triangle. But there is only one constellation Triangulum. It’s a small but ancient star group surrounded by the larger constellations Andromeda to the north and west, Pisces to the southwest, Aries to the south, and Perseus to the northeast. While modest, Triangulum hosts many fine sights for stargazers on a northern autumn (or southern spring) evening. Look for it about 10º due south of the star Almaak (γ Andromedae) and just northeast of Aries [Read more…] about A Trek Through Triangulum

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Filed Under: Stargazing double stars, galaxy, star cluster, triangulum

The Wonderful Star

October 19, 2018 by Brian Ventrudo Filed Under: Stargazing

The red giant star Mira A, a highly evolved variable red giant star, and Mira B a small but dense white dwarf. Image at left was created with data from NASA’s Chandra X-Ray Observatory. The image at right is an artist’s conception of this interacting star system. Credit: X-ray image courtesy NASA/CXC/SAO/M. Karovska et al.; Illustration: CXC/M.Weiss.

As a reader of Cosmic Pursuits, you no doubt believe that all stars are wonderful. But one star, it turns out, is more wonderful than most. The star Mira, or Omicron Ceti, in the constellation Cetus, has been known since ancient times, but its nature began to emerge in the 16th century when a German pastor and amateur astronomer discovered the star’s brightness changed periodically, by a huge amount, every eleven months. And it was but the first discovered of many such stars. [Read more…] about The Wonderful Star

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Filed Under: Stargazing

The Greatest Astrophoto in History (So Far)

October 11, 2018 by Brian Ventrudo Filed Under: History and Famous Astronomers

Fifty years ago this December, at the end of a ghastly year of assassinations, riots, war, and political unrest, three astronauts became the first humans to leave the gravitational embrace of Earth, orbit another world, and return safely back home. Apollo 8 was a mission of astonishing audacity, put together in great haste to counter a possible Soviet lunar mission which U.S. intelligence sources believed was imminent. And it served as a major step to fulfill President Kennedy’s promise to land a man on the Moon and return him safely to Earth by the end of the 1960s [Read more…] about The Greatest Astrophoto in History (So Far)

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Filed Under: History and Famous Astronomers

Algol, the “Demon Star”

September 26, 2018 by Brian Ventrudo Filed Under: Science

An artist’s conception of an eclipsing binary star.

Algol, the second brightest star in the northern constellation Perseus, is the finest example of an eclipsing variable star in the entire sky. In this compact stellar system, two stars revolve around their common center of mass in a rhythmic and precise gravitational dance, and the resulting eclipse causes the brightness of the star to vary like clockwork to a degree that’s easily perceptible to the human eye. And you can watch it from your backyard. No telescope required [Read more…] about Algol, the “Demon Star”

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Filed Under: Science

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