WHL0137-LS

WHL0137-LS, also known as Earendel, is a star in the constellation of Cetus. Discovered in 2022 by the Hubble Space Telescope, it is the earliest and most distant known star, at a comoving distance of 28 billion light-years (8.6 billion parsecs).[2][4] The previous furthest known star, MACS J1149 Lensed Star 1, also known as Icarus, at a comoving distance of 14.4 billion light-years (4.4 billion parsecs),[5] was discovered by Hubble in 2018.[4] Stars like Earendel can be observed at cosmological distances thanks to the large magnification factors involved, that can exceed 1000. Other stars have been observed through this technique, such as Godzilla.

"Earendel (star)" redirects here. For the Germanic mythological figure, see Aurvandil. For the Tolkien topic, see Earendil.

WHL0137-LS

James Webb Space Telescope image of galaxy cluster WHL0137-08 and Earendel
Observation data
Epoch J2000      Equinox J2000
Constellation Cetus
Right ascension 01h 37m 23.232s[1]
Declination –8° 27′ 52.20″[1]
Astrometry
DistanceComoving distance: 28 billion ly[2]
Characteristics
Spectral type B[3]
Apparent magnitude (F435W) 27.2[1]
Details[1]
Mass50–100 M☉
Temperature>20,000 K
Other designations

Observation

Earendel's discovery by the Hubble Space Telescope was reported on 30 March 2022.[1][6] The star was detectable due to gravitational lensing caused by the presence of the galaxy cluster WHL0137-08 between it and the Earth, concentrating the light from the star.[4] Computer simulations of the lensing effect suggest that Earendel's brightness was magnified between one thousand and forty thousand times.[7] The dates of Hubble's exposure to the star's light were 7 June 2016, 17 July 2016, 4 November 2019, and 27 November 2019.[8]

Earendel imaged by the Hubble Space Telescope

The star was nicknamed Earendel by the discoverers, derived from the Old English name for 'morning star' or 'rising light'.[1][9] Eärendil is also the name of a half-elven character in one of J. R. R. Tolkien's books, The Silmarillion, who travelled through the sky with a radiant jewel that appeared as bright as a star. NASA astronomer Michelle Thaller confirmed that the reference to Tolkien was intentional.[10] The star's host galaxy, WHL0137-zD1, was nicknamed "Sunrise Arc", because gravitational lensing distorted its light into a long crescent.[11][12]

Further observations by Hubble and the James Webb Space Telescope have been proposed to better define the properties of the star.[1][13] James Webb's higher sensitivity is expected to allow the analysis of Earendel's stellar spectra and determine whether it is actually a single star.[2][14] The spectral analysis would reveal the presence of elements heavier than hydrogen and helium, if any.[11]

On 30 July 2022, an image of Earendel was captured by the James Webb Space Telescope during its first imaging campaign of the star.[15]

On 8 August 2023, the colors of Earendel were detected, and an image was captured by both the Hubble and Webb telescopes.[16] Based on Webb's NIRCam data, Earendel is a "massive B-type star more than twice as hot as our Sun, and about a million times more luminous".[3]

Physical properties

The light detected from Earendel was emitted 900 million years after the Big Bang.[17][7] The star has been determined to have a 6.2±0.1 redshift,[1] meaning the light from Earendel reached Earth 12.9 billion years later.[18] However, due to the expansion of the universe, the star's observed position is now 28 billion light-years away.[2] The previous most distant star, MACS J1149 Lensed Star 1, has a redshift of 1.49, and is now 14.4 billion light-years away.

As observed, Earendel is likely to have a mass of between 50 and 100 solar masses,[19] and an effective surface temperature of at least 20,000 K (20,000 °C; 36,000 °F).[1] Stars this large usually explode as a supernova just a few million years after forming.[lower-alpha 1][19][20] Although unlikely, Earendel has a small probability of being a population III star, meaning it would contain almost no elements other than primordial hydrogen and helium.[4]

See also

Notes
  1. Due to the timeframes involved, such a supernova would have occurred billions of years ago. From a scientific point of view, the star's currently-observed properties can also be referred to in the present and/or future tense on account of the fact the star's light is visible to us now and its existence is therefore considered to be a part of our present world.

References
  1. Welch, Brian; et al. (21 January 2022). "A Highly Magnified Star at Redshift 6.2". Nature. 603 (7903): 1–50. arXiv:2209.14866. Bibcode:2022Natur.603..815W. doi:10.1038/s41586-022-04449-y. PMID 35354998. S2CID 247842625.
  2. Kabir, Radifah (31 March 2022). "Hubble Detects Earendel, The Farthest Star Ever Seen. It's 28 Billion Light Years Away". ABP Live. ABP News. Archived from the original on 31 March 2022. Retrieved 31 March 2022.
  3. Yan, Isabelle (8 August 2023). "Webb Reveals Colors of Earendel, Most Distant Star Ever Detected". NASA. Retrieved 15 August 2023.
  4. Gianopoulos, Andrea (30 March 2022). "Record Broken: Hubble Spots Farthest Star Ever Seen". NASA. Archived from the original on 30 March 2022. Retrieved 30 March 2022.
  5. Staff (2018). "Cosmological information and results: redshift z=1.49". Wolfram Alpha. Retrieved 4 April 2018.
  6. "Record Broken: Hubble Spots Farthest Star Ever Seen". Space Telescope Science Institute. NASA. 30 March 2022. Archived from the original on 30 March 2022. Retrieved 30 March 2022.
  7. Timmer, John (30 March 2022). "Hubble picks up the most distant star yet observed". Nature. Ars Technica. doi:10.1038/s41586-022-04449-y. Archived from the original on 30 March 2022. Retrieved 30 March 2022.
  8. "Lensed Star Earendel". HubbleSite.org. 30 March 2022. Retrieved 2 April 2022.
  9. Parks, Jake (30 March 2022). "Hubble spots the farthest star ever seen". Astronomy. Archived from the original on 31 March 2022. Retrieved 30 March 2022.
  10. Gohd, Chelsea (31 March 2022). "Meet Earendel: Hubble telescope's distant star discovery gets a Tolkien-inspired name". Space.com. Archived from the original on 31 March 2022. Retrieved 31 March 2022.
  11. Rauchhaupt, Ulf von (31 March 2022). "Der früheste Stern" [The earliest star]. FAZ.NET (in German). Archived from the original on 31 March 2022. Retrieved 31 March 2022.
  12. Rennert, David (31 March 2022). "Hubble-Teleskop erspähte den mit Abstand fernsten Stern" [Hubble telescope spotted by far the most distant star]. Der Standard (in German). Retrieved 3 April 2022.
  13. Coe, Dan; Welch, Brian; Acebron, Ana; Avila, Roberto; Bradac, Marusa; Bradley, Larry; Diego, Jose M.; Dimauro, Paola; Farag, Ebraheem; Florian, Michael; Frye, Brenda Louise; Jimenez-Teja, Yolanda; Kelly, Patrick; Mahler, Guillaume; O'Connor, Kyle; Oguri, Masamune; Rigby, Jane R.; Rodney, Steve; Sharon, Keren; Strait, Victoria; Strolger, Louis-Gregory; Timmes, Frank; Vikaeus, Anton Filip; Windhorst, Rogier A.; Zackrisson, Erik; Zitrin, Adi; De Mink, Selma E. (2021). "Monitoring Earendel, the Lensed z 6 Star". HST Proposal: 16668. Bibcode:2021hst..prop16668C.
  14. Starr, Michelle (30 March 2022). "The Most Distant Single Star Was Just Detected, as Ancient as The Cosmic Dawn". ScienceAlert. Nature. doi:10.1038/s41586-022-04449-y. Archived from the original on 31 March 2022. Retrieved 30 March 2022.
  15. Pultarova, Tereza (2 August 2022). "James Webb Space Telescope glimpses Earendel, the most distant star known in the universe". Space. Retrieved 2 August 2022.
  16. Yan, Isabelle (8 August 2023). "Webb Reveals Colors of Earendel, Most Distant Star Ever Detected". NASA. Retrieved 9 August 2023.
  17. Letzter, Rafi (30 March 2022). "Meet Earendel, the most distant star ever detected". The Verge. Archived from the original on 30 March 2022. Retrieved 30 March 2022.
  18. Gianopoulos, Andrea (29 March 2022). "Record Broken: Hubble Spots Farthest Star Ever Seen". NASA.
  19. Konitzer, Franziska (30 March 2022). "Entferntester Stern dank 1000-facher Vergrößerung entdeckt" [Furthest star discovered thanks to 1000x magnification]. Spektrum der Wissenschaft (in German). Archived from the original on 31 March 2022. Retrieved 31 March 2022.
  20. Dunn, Marcia (30 March 2022). "This is Earendel, the most distant star ever seen by humans". Los Angeles Times. Archived from the original on 30 March 2022. Retrieved 31 March 2022.
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