Stars Archives

September 21, 2023September 21, 2023 by Brian Koberlein

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.

September 18, 2023September 18, 2023 by Evan Gough

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)

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.

September 8, 2023September 8, 2023 by Evan Gough

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.

August 25, 2023August 25, 2023 by Brian Koberlein

A Giant Black Hole Destroyed a Star and Threw the Pieces Into Space

Illustration of the black hole ASASSN-14li. Credit: NASA/CXC/M.Weiss

When a black hole consumes a star, things can get quite messy. Take, for example, the event known as ASASSN-14li, where a massive star strayed too close to a supermassive black hole and paid the ultimate price.

August 12, 2023August 12, 2023 by Brian Koberlein

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.

August 12, 2023August 12, 2023 by Matt Williams

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.

August 10, 2023August 10, 2023 by Carolyn Collins Petersen

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

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.

August 4, 2023August 4, 2023 by Carolyn Collins Petersen

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.

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.

July 30, 2023July 30, 2023 by Brian Koberlein

New Simulation Reveals the Churning Interiors of Giant Stars

A simulation of convection within a star. Credit: E.H. Anders et al

On a basic level, a star is pretty simple. Gravity squeezes the star trying to collapse it, which causes the inner core to get extremely hot and dense. This triggers nuclear fusion, and the heat and pressure from that pushes back against gravity. The two forces balance each other while a star is in its main sequence state. Easy peasy. But the details of how that works are extremely complex. Modeling the interior of a star accurately requires sophisticated computer models, and even then it can be difficult to match a model to what we see on the surface of a star. Now a new computer simulation is helping to change that.

July 29, 2023July 29, 2023 by Carolyn Collins Petersen

Astronomers are Watching a Planet Get its Atmosphere Blasted Away into Space

This artist's illustration shows a planet (dark silhouette) passing in front of the red dwarf star AU Microscopii. The planet is so close to the eruptive star a ferocious blast of stellar wind and blistering ultraviolet radiation is heating the planet's hydrogen atmosphere, causing it to escape into space. The illustration is based on measurements made by the Hubble Space Telescope. Credits: NASA, ESA, and Joseph Olmsted (STScI)

What do you get when a hot young world orbits a wildly unstable young red dwarf? For AU Microsopii b, the answer is: flares from the star tearing away the atmosphere. That catastrophic loss happens in fits and starts, “hiccuping” out its atmosphere at one point and then losing practically none the next.