The most farthest stars ever discovered may be misclassified. Instead of being a single star, an object called Erendel from the old English word “morningstar” could be a group of stars that are linked by gravity and formed from clouds of gas and dust, new research suggests.
Discovered by the Hubble Space Telescope in 2022, Adel was considered a star formed only 900 million years after the Big Bang, when the universe was only 7% of its current age.
Now, in a survey published on July 31st in the Astrophysical Journal, Astronomers saw a new look at Earendel using James Webb Space Telescope (JWST). They wanted to explore the possibility that Earendel could be a compact star cluster, rather than a single star or a binary system, as previously thought.
You might like it
They found that the spectral function of Earendel was that spherical clusters (a type of star cluster) matched those found in the local universe.
“What makes me feel at ease with this work is that if Earendel is truly a star cluster, it’s not unexpected!” Massimo Pascale, a doctoral student in astronomy at the University of California, Berkeley and a lead author of the study, told Live Science in an email. “[This] The work finds that Irendel appears to be in quite a line with the way in which the spherical clusters seen in local universes are expected to have seen in the first billion years of the universe. ”
Ancient objects
Located in the Sunrise Ark Galaxy, 12.9 billion light-years from the US, Erendel was discovered in a phenomenon known as a gravity lens. This is a phenomenon predicted by Einstein’s general theory of relativity, in which large objects bend the light passing through them. The huge clusters of galaxies located between Earth and Erendel are so large that they distort the fabric of space-time and create an enlarged effect that allows astronomers to observe the light of Erendel. Research shows that the stars look at least 4,000 times larger due to this gravity lens effect.
This expansion is the strongest in some special regions. If a star or galaxy is right next to one of these regions, the image can be enlarged hundreds or thousands of times larger than usual. Irendel appears to be sitting very close to one of these “sweet spots.” Therefore, you can see it even if you are almost 12.9 billion light years away. Such near-perfect alignments are extremely rare, and astronomers have considered alternative explanations beyond a single star.
Related: Titans staring directly at us in stunning 15-year time-lapse photos, the “eyes” of the universe stared directly at us
After the discovery of Earendel in 2022, researchers analyzed the objects using data from JWST’s Near Infrared Imager (NIRCAM). By examining its brightness and size, they concluded that Erendel is more than twice as hot as the sun, and could be a star that is about a million times brighter than ours. In the colours of Erendel, astronomers have also discovered hints about the existence of cooler companion stars.
“After some recent studies showed that in fact, Erendel was (not necessarily) much larger than previously thought, then I’ve come to believe it’s worth exploring the star cluster scenario,” Pascare said.
Using spectroscopic data from JWST’s NirSpec Instruments, Pascale and Team studied Earendel’s age and metal content.
The team looked at the Earendel spectroscopic continuum. This essentially shows how to smoothly change light of different wavelengths of brightness. This pattern coincided with what was expected from the star cluster, and at least coincided with the total light of multiple stars.
“A new part of this research is the NIRSPEC spectrum, which provides a little more detail than NIRCAM data can,” says Brian Welch, a postdoctoral researcher at the NASA Goddard Space Flight Center, who discovered Erendel in 2022 but was not involved in the new research.
However, Welch does not believe that the new data is sufficient to confirm that Earendel is a star cluster.
“In NIRSPEC’s spectral resolution [instrument]the spectra of the stars and star clusters with lenses are very similar. So, when trying to classify these highly expanded objects, it is important to consider all available data,” Welch told Live Science in an email.
Researchers have only investigated the possibility of a “star cluster.” We investigated all possible scenarios, such as Earendel being a single-star or multi-star system, and did not compare results.
“The measurements are robust and well-made, but taking into account the Star Cluster hypothesis alone limits the scope of this study,” Welch said.
Both Pascale and Welch agreed that the key to solving Earendel’s mystery is to monitor the microlens effect. A microlens is a subtype of gravity lens in which the passing objects temporarily distort the image of a distant object when the object passed through passes and nearby objects lined up in front of it. The change in brightness due to microlenses is more pronounced when distant objects are small rather than much larger star clusters, such as stars, planets, and star systems.
“It’s exciting to see what future JWST programs can do to make the nature of Erendel even more clear,” Pascare said.
Source link
