Tag Archives: Fomalhaut

NASA Night Sky Notes: Chill Out: Spot An Ice Giant In August

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. Your tax dollars help promote science! The following article was provided for reprinting by the Night Sky Network in August, 2019.

By David Prosper

Is the summer heat getting to you? Cool off overnight while spotting one of the solar system’s ice giants: Neptune! It’s the perfect way to commemorate the 30th anniversary of Voyager 2’s flyby.

Neptune is too dim to see with your unaided eye so you’ll need a telescope to find it. Neptune is at opposition in September, but its brightness and apparent size won’t change dramatically as it’s so distant; the planet is usually just under 8th magnitude and 4.5 billion kilometers away. You can see Neptune with binoculars but a telescope is recommended if you want to discern its disc; the distant world reveals a very small but discernible disc at high magnification. Neptune currently appears in Aquarius, a constellation lacking in bright stars, which adds difficulty to pinpointing its exact location. Fortunately, the Moon travels past Neptune the night of August 16th, passing less than six degrees apart (or about 12 Moon widths) at their closest. If the Moon’s glare overwhelms Neptune’s dim light, you can still use the its location that evening to mark the general area to search on a darker night. Another Neptune-spotting tip: Draw an imaginary line from bright southern star Fomalhaut up to the Great Square of Pegasus, then mark a point roughly in the middle and search there, in the eastern edge of Aquarius. If you spot a blue-ish star, swap your telescope’s eyepiece to zoom in as much as possible. Is the suspect blue “star” now a tiny disc, while the surrounding stars remain points of white light? You’ve found Neptune!

Neptune and Uranus are ice giant planets. These worlds are larger than terrestrial worlds like Earth but smaller than gas giants like Jupiter. Neptune’s atmosphere contains hydrogen and helium like a gas giant, but also methane, which gives it a striking blue color. The “ice” in “ice giant” refers to the mix of ammonia, methane, and water that makes up most of Neptune’s mass, located in the planet’s large, dense, hot mantle. This mantle surrounds an Earth-size rocky core. Neptune possesses a faint ring system and 13 confirmed moons. NASA’s Voyager 2 mission made a very close flyby on August 25, 1989. It revealed a dynamic, stormy world streaked by the fastest winds in the solar system, their ferocity fueled by the planet’s surprisingly strong internal heating. Triton, Neptune’s largest moon, was discovered to be geologically active, with cryovolcanoes erupting nitrogen gas and dust dotting its surface, and a mottled “cantaloupe” terrain made up of hard water ice. Triton is similar to Pluto in size and composition, and orbits Neptune in the opposite direction of the planet’s rotation, unlike every other large moon in the solar system. These clues lead scientists to conclude that this unusual moon is likely a captured Kuiper Belt object.

Discover more about Voyager 2, along with all of NASA’s past, present, and future missions, at nasa.gov

Clockwise from top left: Neptune and the Great Dark Spot traced by white clouds; Neptune’s rings; Triton and its famed icy cantaloupe surface; close of up Triton’s surface, with dark streaks indicating possible cyrovolcano activity. Find more images and science from Voyager 2’s flyby at bit.ly/NeptuneVoyager2 Image Credit: NASA/JPL
Finder chart for Neptune. This is a simulated view through 10×50 binoculars (10x magnification). Please note that the sizes of stars in this chart indicate their brightness, not their actual size. Moon image courtesy NASA Scientific Visualization Studio; chart created with assistance from Stellarium.

The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach. Visit nightsky.jpl.nasa.gov to find local clubs, events, and more!

AAVSO Writer’s Bureau Digest For 20 December 2013

2013dec20_aavso_logoThe AAVSO Writer’s Bureau, hosted by the American Association of Variable Star Observers (www.aavso.org), is a selective aggregator of high-quality science content for the amateur astronomer. Several astronomy bloggers, science writers, and official astronomy publishers and organizations provide articles free-of-charge for redistribution through the AAVSO-WB. The five most recent Writer’s Bureau posts are presented below with direct links to the full articles on the author’s own website. CNYO thanks the authors and the AAVSO for making these articles available for free to all astronomy groups!

Will This New Technology Transform Astronomy?

By Monica Young, Sky & Telescope

2013dec20_Arp147_341pxBack in my former life, I was an X-ray astronomer. While optical astronomy charged ahead with camera technology that benefitted from commercial investment (hello, smartphones), the X-ray detectors I worked with were of a more “homebrew” variety (really good homebrew). 

If I point an X-ray telescope at, say, a distant quasar for a few hours, I might get a few hundred photons if I’m lucky. Compare that with an optical image, where the same quasar might emit millions of photons. As a professor of mine once joked, X-rays are so few and far between, they should have names: “Look, there go Peter, Jill, and Harry.”

Read the full article at: skyandtelescope.com/news/Will-This-Cutting-Edge-Technology…

This Neutron Star Behaves Just Like The Hulk

By Elizabeth Howell, Universe Today

2013dec20_transformWhen Bruce Banner gets angry, he gets big and green and strong and well, vengeful. The Hulk is the stuff of comic book legend and as Mark Ruffalo recently showed us in The Avengers, Banner’s/Hulk’s personality can transform on a dime.

Turns out rapid transformations are the case in astronomy, too! Scientists found a peculiar neutron star that can change from radio pulsar, to X-ray pulsar, back and forth. In the Hulk’s case, a big dose of gamma rays likely fuelled his ability to transform. This star’s superpowers, however, likely come from a companion star.

Read the full article at: www.universetoday.com/105039/this-neutron-star-behaves…

Fomalhaut Star System Actually A Triple

Monica Young, Sky & Telescope

2013dec20_Fomalhaut_planet_341pxFomalhaut itself is a regular A-class star, twice the size of the Sun, accompanied by a smaller, K-class companion. The system made headlines in 2008 when astronomers discovered the controversial exoplanet candidate Fomalhaut b. Even after the dust mostly settled, the planet’s highly elliptical orbit remained unexplained.

It’s unclear whether the planet’s orbit is aligned with the far-out debris disk that rings the young star. And stranger still, the debris disk itself is off-kilter, its center offset from Fomalhaut A by 15 times the Earth-Sun distance.

Read the full article at: www.skyandtelescope.com/community/skyblog/newsblog/…

Power Of Multiple Amateur Telescopes, UNITE!

Phil Plait, Bad Astronomy

2013dec20_uniteTaking pictures of astronomical objects is a lot like collecting rainwater in buckets. Photons from your target are the rain, and your telescope is the bucket. The bigger the bucket, the more rain you collect. You get more water if you leave the bucket out longer, too.

So astronomers like to use big telescopes and long exposure times to get faint detail in their cosmic portraits. However, there’s a third option: Use more than one bucket.

Read the full article at: www.slate.com/blogs/bad_astronomy/2013/09/15/astrophoto_planetary_nebula_image_combining…

Old, Fat Stars Flicker

Mark Zastrow, Sky & Telescope

2013dec20_solar_granulation_341pxWhen you look through a telescope at a star glowing red, you might ponder: is it skinny or fat?

Although so-called red dwarfs and red giants have the same temperature, the distinction between them is profound. Red dwarfs are half the mass of the Sun or smaller. A red giant can be many times the mass of the Sun. It’s also about to die — low on energy, it’s bloated to as much as 1,500 times the radius of the Sun.

Read the full article at: skyandtelescope.com/community/skyblog/…