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

This artist's concept illustrates a young, red dwarf star surrounded by three planets. There's growing evidence that red dwarfs place serious limits on exoplanet habitability. Image Credit: By NASA/JPL-Caltech - NASA Image of the Day, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17104843

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.

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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.

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We Can't See the First Stars Yet, but We Can See Their Direct Descendants

This artist’s impression shows a Population III star that is 300 times more massive than our Sun exploding as a pair-instability supernova. Credit: NOIRLab/NSF/AURA/J. da Silva/Spaceengine

If you take a Universe worth of hydrogen and helium, and let it stew for about 13 billion years, you get us. We are the descendants of the primeval elements. We are the cast-off dust of the first stars, and many generations of stars after that. So our search for the first stars of the cosmos is a search for our own history. While we haven’t captured the light of those first stars, some of their direct children may be in our own galaxy.

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It’s Like Looking at the Infant Sun: Webb Captures Image of an Energetic Young Star

NASA’s James Webb Space Telescope’s high resolution, near-infrared look at Herbig-Haro 211 reveals exquisite detail of the outflow of a newly forming young star, an infantile analogue of our Sun. Image Credit: ESA/Webb, NASA, CSA, Tom Ray (Dublin)
NASA’s James Webb Space Telescope’s high resolution, near-infrared look at Herbig-Haro 211 reveals exquisite detail of the outflow of a newly forming young star, an infantile analogue of our Sun. Image Credit: ESA/Webb, NASA, CSA, Tom Ray (Dublin)

Ever wondered what our young Sun might have looked like in its infancy some five billion years ago?

The audacious JWST has captured an image of a very young star much like our young Sun, though the star itself is obscured. Instead, we see supersonic jets of gas. Young stars can blast out jets of material as they form, and the jets light up the surrounding gas. The luminous regions created by the jets as they slam into the gas are called Herbig-Haro Objects.

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A Black Hole Nibbles on a Star Every 22 Days, Slowly Consuming it

A star is ripped apart by a black hole. Credit: Mark Garlick

Astronomers working with NASA’s Neil Gehrels Swift Observatory have spotted something unusual. The observatory’s X-Ray Telescope (XRT) has captured emissions from a supermassive black hole (SMBH) in a galaxy about 500 million light-years away. The black hole is repeatedly feeding on an unfortunate star that came too close.

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Giant Tidal Waves are Crashing Onto the Surface of an Enormous Star

Illustration of waves breaking on a heartbeat star. Credit: Melissa Weiss, CfA

Binary star systems often appear as variable stars. When we can’t see the individual stars because they are either too close together or too far away, we can see the gradual brightening and dimming of a single point of light as the stars orbit each other. Sometimes if the stars are particularly close when they pass each other they can brighten in unusual ways. One example of this is known as a heartbeat star.

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Astronomers Find a Newly-Forming Quadruple-Star System

This artist’s impression shows the orbits of the objects in the HR 6819 triple system. Credit: ESO/L. Calçada

In a surprising find, the international ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP) team recently observed a young quadruple star system within a star-forming region in the Orion constellation. The discovery was made during a high-resolution survey of 72 dense cores in the Orion Giant Molecular Clouds (GMCs) using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. These observations provide a compelling explanation for the origins and formation mechanisms of binary and multiple-star systems.

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JWST Turns its Gaze on the Farthest Known Star: Earendel

The massive galaxy cluster called WHL0137-08, which is gravitational lensing the most strongly magnified galaxy known in the Universe’s first billion years: the Sunrise Arc, and within that galaxy, the most distant star ever detected. The star is , nicknamed Earendel. NASA, ESA, CSA, D. Coe (AURA/STScI for ESA), Z. Levay
The massive galaxy cluster called WHL0137-08, which is gravitational lensing the most strongly magnified galaxy known in the Universe’s first billion years: the Sunrise Arc, and within that galaxy, the most distant star ever detected. The star is , nicknamed Earendel. NASA, ESA, CSA, D. Coe (AURA/STScI for ESA), Z. Levay

In March 2022, astronomers announced the discovery of the farthest known star via an image taken by the Hubble Space Telescope. They named it Earendel, after the old English name for “morning star”. Now, JWST’s Near-infrared Camera (NIRCam) and its NIRSpec spectrometer have taken a look at the same star and revealed more details about it.

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Yes! A JWST Image of the Ring Nebula

JWST/NIRcam composite image of the Ring Nebula. The images clearly show the main ring, surrounded by a faint halo and with many delicate structures. The interior of the ring is filled with hot gas. The star which ejected all this material is visible at the very center. Courtesy JWST/University of Manchester.
JWST/NIRcam composite image of the Ring Nebula. The images clearly show the main ring, surrounded by a faint halo and with many delicate structures. The interior of the ring is filled with hot gas. The star which ejected all this material is visible at the very center. Courtesy JWST/University of Manchester.

Brace yourselves for great JWST views of the iconic Ring Nebula (M57). An international team of astronomers just released a fantastic near-infrared image of the nebula, showing incredible details.

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