Cosmic Pursuits

Basic astronomy and night sky information

Brian Ventrudo

Barnard’s Star Has a Planet After All

By Filed Under: Science

An artist’s impression of the newly discovered planet round Barnard’s star, the nearest single star to the Sun The newly discovered planet is the second-closest known exoplanet to the Earth and orbits the fastest moving star in the night sky. Image credit: ESO/M. Kornmesser.

It was a discovery nearly a century in the making, but astronomers have finally detected a planet around the speedy little red dwarf known as Barnard’s Star. The existence of the planet is not particularly surprising given the vast harvest of exoplanets discovered since 1995 around all manner of stars. Nor is the planet a habitable world, to be sure. But it was welcome news nonetheless to find that the nearest single star to Earth has at least one planet in its relatively feeble gravitational embrace.

In many ways, Barnard’s Star was the “white whale” of exoplanet hunters. That’s because the star is close, just six light years away, the second-closest star system to Earth, which should make it easier to find an orbiting planet. And the star is prominent because of its speedy apparent motion across the sky. Barnard’s Star is also old, more than twice the age of our own solar system, so it’s had plenty of time to form a planetary system. But for nearly a hundred years, astronomers have examined the star for evidence of a planetary system using visual observation, photographic imaging, and finally using modern spectroscopic planet-hunting techniques. They came up empty every time [Read more…] about Barnard’s Star Has a Planet After All

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The Cat’s Eye Nebula

By 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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A Trek Through Triangulum

By 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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The Wonderful Star

By 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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The Greatest Astrophoto in History (So Far)

By 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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