Stars Archives

November 16, 2023November 16, 2023 by Evan Gough

JWST Follows Neon Signs Toward New Thinking on Planet Formation

This artist's illustration shows the young star SZ Chamaeleontis (SZ Cha). SZ Cha is surrounded by a protoplanetary disk of gas and dust. Planets may form in the disk, but they're running out of time. Image Credit: NASA, ESA, CSA, Ralf Crawford (STScI)

Everyone knows that the James Webb Space Telescope is a ground-breaking infrared space telescope that’s helping us better understand the cosmos. The JWST’s discerning infrared eyes are deepening our understanding of everything from exoplanets to primitive galaxies to the birth of stars.

But it’s not the first ground-breaking infrared space telescope we’ve launched. There was IRAS, then ISO, then the Spitzer Space Telescope. The Spitzer is the JWST’s most recent infrared predecessor, and the JWST is observing one of the same targets that the Spitzer did, taking note of some puzzling changes.

November 9, 2023November 9, 2023 by Evan Gough

Astronomers Find Dozens of Massive Stars Fleeing the Milky Way

This is Zeta Ophiuchi, a runaway star observed by Spitzer. The star is creating a bow shock as it travels through an interstellar dust cloud. A new study found dozens of new runaway stars in the Milky Way. Image Credit: NASA/JPL-Caltech

The Milky Way can’t hold onto all of its stars. Some of them get ejected into intergalactic space and spend their lives on an uncertain journey. A team of astronomers took a closer look at the most massive of these runaway stars to see what they could find out how they get ejected.

November 8, 2023November 8, 2023 by Mark Thompson

Astronomers are Hoping to Detect Gravitational Waves Coming from Supernova 1987A

This Hubble Space Telescope image shows Supernova 1987A within the Large Magellanic Cloud, a neighboring galaxy to our Milky Way. — Hubble Space Telescope image of SN1987A in the Large Magellanic Cloud (Credit : NASA)

A supernova explosion is a cataclysmic explosion that marks the violent end of a massive star’s life. During the event, the star releases immense amounts of energy, often outshining the combined light from all the stars in the host galaxy for a very brief period of time. The explosion produces heavy elements and spreads them out among the stars to contribute to the formation of new stars and planets. The closest supernova in recent years occurred in the Large Magellanic Cloud in 1987 (SN1987A) and now, a team of astronomers have searched through mountains of data to see if they can detect gravitational waves from the remnant.

November 6, 2023November 6, 2023 by Evan Gough

This is a First. An Exoplanet in a Polar Circumbinary Disc Surrounding Two Stars.

This illustration shows a binary star surrounded by a thick disc of material in a polar orbit. Copyright and credit: University of Warwick/Mark Garlick

We live in an age of exoplanet discovery. One thing we’ve learned is not to be surprised by the kinds of exoplanets we keep discovering. We’ve discovered planets where it might rain glass or even iron, planets that are the rocky core remnants of gas giants stripped of their atmospheres, and drifting rogue planets untethered to any star.

October 31, 2023October 31, 2023 by Evan Gough

Did Betelgeuse Consume a Smaller Star?

The red supergiant Betelgeuse. Its activity can be confounding, and new research suggests that the star could've consumed a smaller companion star. Image credit: Hubble Space Telescope. Image Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella

What’s going on with Betelgeuse? In recent years it’s generated a lot of headlines as its luminosity has shifted dramatically several times. The red supergiant brightened by almost 50% earlier this year, triggering speculation that it may go supernova.

But new research suggests there’s something completely different happening with Betelgeuse that has nothing to do with its recent fluctuations. It may have consumed a smaller companion star.

October 31, 2023November 1, 2023 by Evan Gough

Three Planets Around this Sunlike Star are Doomed. Doomed!

A distant Sun-like star will leave the main sequence behind, ending its life of fusion. Then it'll expand into a red giant, totally destroying its four planets. Image Credit: fsgregs Creative Commons Attribution-Share Alike 3.0 Unported

According to new research we can start writing the eulogy for four exoplanets around a Sun-like star about 57 light years away. But there’s no hurry; we have about one billion years before the star becomes a red giant and starts to destroy them.

October 27, 2023October 27, 2023 by Evan Gough

What’s the Best Way to Find Planets in the Habitable Zone?

This artist's illustration of Kepler 22-b, an Earth-like planet in the habitable zone of a Sun-like star about 640 light years (166 parsecs) away. Credit: NASA/Ames/JPL-Caltech

Despite the fact that we’ve discovered thousands of them, exoplanets are hard to find. And some types are harder to find than others. Naturally, some of the hardest ones to find are the ones we most want to find. What can we do?

Keep working on it, and that’s what a trio of Chinese scientists are doing.

October 26, 2023October 26, 2023 by Evan Gough

An Exo-Neptune Beat the Odds and Kept its Atmosphere

An artist impression of exoplanet LTT9779b orbiting its host star. Credit: Ricardo Ramírez Reyes (Universidad de Chile)

As planet-hunting scientists find more and more planets, they’ve encountered some puzzles. One of them concerns the lack of Neptune-size worlds orbiting close to their stars. Astronomers think that these planets aren’t massive enough to retain their atmospheres in the face of their stars’ powerful radiation, which strips it away.

But at least one of these planets has retained its atmosphere. How?

October 20, 2023October 20, 2023 by Evan Gough

Do Red Dwarfs or Sunlike Stars Have More Earth-Sized Worlds?

This artist's concept illustrates a red dwarf star surrounded by exoplanets. Credit: NASA/JPL-Caltech

Earth is our only example of a habitable planet, so it makes sense to search for Earth-size worlds when we’re hunting for potentially-habitable exoplanets. When astronomers found seven of them orbiting a red dwarf star in the TRAPPIST-1 system, people wondered if Earth-size planets are more common around red dwarfs than Sun-like stars.

But are they? Maybe not.

October 6, 2023October 6, 2023 by Brian Koberlein

What Caused Eta Carinae’s 1840 “Great Eruption?”

Hubble image of Eta Carinae. Credit: NASA, ESA, N. Smith (University of Arizona), and J. Morse (BoldlyGo Institute)

In 1840 an unassuming star in the Southern Hemisphere brightened suddenly. What had been a 5th magnitude star became so bright by 1843 that it was the second brightest star in the sky. The star, known as Eta Carinae, had been known to vary in brightness before, but this change was so sudden and so dramatic that it became known as the Great Eruption.