Tag Archives: Extrasolar Planet

NASA Night Sky Notes: Summer Triangle Corner – Vega

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 June, 2020.

By David Prosper and Vivian White

If you live in the Northern Hemisphere and look up during June evenings, you’ll see the brilliant star Vega shining overhead. Did you know that Vega is one of the most studied stars in our skies? As one of the brightest summer stars, Vega has fascinated astronomers for thousands of years.

Vega is the brightest star in the small Greek constellation of Lyra, the harp. It’s also one of the three points of the large “Summer Triangle” asterism, making Vega one of the easiest stars to find for novice stargazers. Ancient humans from 14,000 years ago likely knew Vega for another reason: it was the Earth’s northern pole star! Compare Vega’s current position with that of the current north star, Polaris, and you can see how much the direction of Earth’s axis changes over thousands of years. This slow movement of axial rotation is called precession, and in 12,000 years Vega will return to the northern pole star position. Bright Vega has been observed closely since the beginning of modern astronomy and even helped to set the standard for the current magnitude scale used to categorize the brightness of stars. Polaris and Vega have something else in common, besides being once and future pole stars: their brightness varies over time, making them variable stars. Variable stars’ light can change for many different reasons. Dust, smaller stars, or even planets may block the light we see from the star. Or the star itself might be unstable with active sunspots, expansions, or eruptions changing its brightness. Most stars are so far away that we only record the change in light, and can’t see their surface.

NASA’s TESS satellite has ultra-sensitive light sensors primed to look for the tiny dimming of starlight caused by transits of extrasolar planets. Their sensitivity also allowed TESS to observe much smaller pulsations in a certain type of variable star’s light than previously observed. These observations of Delta Scuti variable stars will help astronomers model their complex interiors and make sense of their distinct, seemingly chaotic, pulsations. This is a major contribution towards the field of astroseismology: the study of stellar interiors via observations of how sound waves “sing” as they travel through stars. The findings may help settle the debate over what kind of variable star Vega is. Find more details on this research, including a sonification demo that lets you “hear” the heartbeat of one of these stars, at: bit.ly/DeltaScutiTESS

Interested in learning more about variable stars? Want to observe their changing brightness? Check out the website for the American Association of Variable Star Observers (AAVSO) at aavso.org. You can also find the latest news about Vega and other fascinating stars at nasa.gov.

Vega possesses two debris fields, similar to our own solar system’s asteroid and Kuiper belts. Astronomers continue to hunt for planets orbiting Vega, but as of May 2020 none have been confirmed. More info: bit.ly/VegaSystem Credit: NASA/JPL-Caltech
Can you spot Vega? You may need to look straight up to find it, especially if observing after midnight.

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!

“Upstate NY Stargazing In March” Article Posted To newyorkupstate.com And syracuse.com

Greetings, fellow astrophiles!

The latest article in the Upstate NY Stargazing series, “Upstate NY Stargazing In March: Messier Marathon and the Lunar Occultation of Aldebaran,” has just been posted to newyorkupstate.com and syracuse.com.

Direct Link: newyorkupstate.com/outdoors/2017/02/…lunar_occultation_of_ald.html

Direct Link: syracuse.com/outdoors/index.ssf/2017/02/…lunar_occultation_of_ald.html

* Prof. Leslie Hebb’s Cazenovia College Science Cafe lecture, “Distant Worlds: What We Know About Extra-Solar Planets And Their Potential For Habitability” was a great success this past Wednesday and we look forward to announcing and co-sponsoring future astro-related events.

* With one day to go and the potential for clear skies, interested parties are encouraged to read up on how to observe – and record – the lunar occultation of Aldebaran on the night of March 4th.

* And, finally, the March article is the perfect time to introduce new observers to Messier Marathons prior to any attempts of the same at month’s end.

Caption: M31, the Andromeda Galaxy, and its satellite galaxies M32 (a hazy star just above-left of M31’s center) and M110 (the oval structure below-left of M31’s center). Photograph taken at Kopernik Observatory & Science Center by Kopernik Astronomical Society member George Normandin. Click for a larger view.

Turning our attention to the North, and in anticipation of a larger discussion about circumpolar constellations, we introduce Ursa Major – a great, easy-to-find constellation with a small fortune in Messier Objects.

Caption: Ursa Major and the Big Dipper, including brightest star labels, the locations of Messier Objects, and an arrow to follow to the north star Polaris. Click for a larger view.