MACS J1149 Lensed Star 1

MACS J1149 Lensed Star 1
NASA-Icarus-MostDistantMainSequenceStar-20180402.jpg
Detection of MACS J1149 Lensed Star 1
A galactic cluster (left) magnified a distant star (now named Icarus) more than 2,000 times, making it visible in 2016 from Earth (lower right), 9.34 billion light-years away—although visible in 2016, the star was not visible in 2011 (upper right).
Observation data
Epoch J2000[1]      Equinox J2000[1]
ConstellationLeo[1][2]
Right ascension11h 49m 35.59s[1]
Declination22° 23′ 47.4″[1]
Astrometry
DistanceRedshift of 1.49 yields comoving distances of 14.4 billion ly
Characteristics
Spectral typeB[2]
Apparent magnitude (V)≈28.4[2] (normally 29.9)[note 1]
Apparent magnitude (R)≈28.2[2] (normally 29.7)
Apparent magnitude (Z)≈27.9[2] (normally 29.4)
Apparent magnitude (J)27.3[2] (normally 28.8)
Apparent magnitude (H)27.4[2] (normally 28.9)
Details
Surface gravity (log g)2 - 4[2] cgs
Temperature11,000 – 14,000[2] K
Metallicity≈0.006[2]
Age~8[2] Myr
Other designations
Icarus, LS1, MACS J1149 LS1, MACS J1149 Lensed Star 1 (LS1), MACS J1149+2223 Lensed Star 1

MACS J1149 Lensed Star 1, also known as Icarus,[note 2] is a blue supergiant star observed through a gravitational lens. It is the second most distant individual star to have been detected so far (second only to WHL0137-LS, a.k.a. Earendel, as of March 2022), at approximately 14 billion light-years from Earth (redshift z=1.49; comoving distance of 14.4 billion light-years; lookback time of 9.34 billion years).[3][2][4][5][6][7][8] Light from the star was emitted 4.4 billion years after the Big Bang.[7] According to co-discoverer Patrick Kelly, the star is at least a hundred times more distant than the next-farthest non-supernova star observed, SDSS J1229+1122, and is the first magnified individual star seen.[4][7]

History

Comparison of observed data of the star Icarus with a model of a blue supergiant star spectrum. Ultraviolet light is redshifted into the visible range and the star appears reddish.

In April and May 2018,[2] the star was found in the course of studying the supernova SN Refsdal with the Hubble Space Telescope. Astronomer Patrick Kelly of the University of Minnesota is the lead author of the finding, published in the journal Nature Astronomy.[2][8]

While astronomers had been collecting images of this supernova from 2004 onward, they recently discovered a point source that had appeared in their 2013 images, and become much brighter by 2016. They determined that the point source was a solitary star being magnified more than 2,000 times by gravitational lensing.[2][4][5][6][7][9] The light from LS1 was magnified not only by the huge total mass of the galaxy cluster MACS J1149+2223—located 5 billion light-years away—but also transiently by another compact object of about three solar masses within the galaxy cluster itself that passed through the line of sight, an effect known as gravitational microlensing.[7][9][10] The galaxy cluster magnification is probably a factor of 600, while the microlensing event, which peaked in May 2016, brightened the image by an additional factor of ~4.[2] There was a second peak near the brightness curve maximum, which may indicate the star was binary.[2] The microlensing body may have been a star or a black hole in the cluster. Continuous monitoring of the star Icarus may one day rule out the possibility that primordial black holes constitute a sizable fraction of dark matter.[9] Normally, the only astronomical objects that can be detected at this range would be either whole galaxies, quasars, or supernovas, but the light from the star was magnified by the lensing effect. They determined the light was from a stable star, not a supernova, as its temperature did not fluctuate; the temperature also allowed them to catalog the star as a blue supergiant.[11] Because the visible light is the redshifted ultraviolet tail, the star does not appear blue to us but reddish or pink.

The light observed from the star was emitted when the universe was about 30% of its current age of 13.8 billion years. Kelly suggested that similar microlensing discoveries could help them identify the earliest stars in the universe.[11]

Name

The formal name MACS J1149 is a reference to MAssive Cluster Survey and the star's coordinates in the J2000 astronomical epoch.

While Kelly had wanted to name the star Warhol, alluding to Andy Warhol's notion of having 15 minutes of fame, the team ended up naming the star Icarus based on the Greek mythological figure.[8]

Astrophysical implications

The discovery shows that astronomers can study the oldest stars in background galaxies of the early universe by combining the strong gravitational lensing effect from galaxy clusters with gravitational microlensing events caused by compact objects in these galaxy clusters.[2][12] By using these events, astronomers can study and test some models about dark matter in galaxy clusters and observe high energy events (supernovae, variable stars) in young galaxies.[9][12][13]

See also

Notes

  1. ^ The microlensing event brightened the star by a factor of 4, or about 1.5 magnitudes. With 600× magnification, it is brightened by 6002 (360,000), which would be an additional magnitude difference of 13.9 magnitudes. Therefore, the star would have Vmag of 43.8 without any lensing effects, thousands of times dimmer than any current or planned telescopes can see.
  2. ^ Other names include LS1, MACS J1149 LS1, MACS J1149 Lensed Star 1 (LS1) and MACS J1149+2223 Lensed Star 1

References

  1. ^ a b c d Kelly, P. L. (2015). "Multiple images of a highly magnified supernova formed by an early-type cluster galaxy lens". Science. 347 (6226): 1123–1126. arXiv:1411.6009. Bibcode:2015Sci...347.1123K. doi:10.1126/science.aaa3350. PMID 25745167. S2CID 206633888.
  2. ^ a b c d e f g h i j k l m n o p q r Kelly, Patrick L.; et al. (2 April 2018). "Extreme magnification of an individual star at redshift 1.5 by a galaxy-cluster lens". Nature Astronomy. 2 (4): 334–342. arXiv:1706.10279. Bibcode:2018NatAs...2..334K. doi:10.1038/s41550-018-0430-3. S2CID 125826925.
  3. ^ Staff (2018). "Cosmological information and results: redshift z=1.49". Wolfram Alpha. Retrieved 4 April 2018.
  4. ^ a b c Jenkins, Ann; Villard, Ray; Kelly, Patrick (2 April 2018). "Hubble Uncovers the Farthest Star Ever Seen". NASA. Retrieved 2 April 2018.
  5. ^ a b Howell, Elizabeth (2 April 2018). "Rare Cosmic Alignment Reveals Most Distant Star Ever Seen". Space.com. Retrieved 2 April 2018.
  6. ^ a b Sanders, Robert (2 April 2018). "Hubble peers through cosmic lens to capture most distant star ever seen". Berkeley News. Retrieved 2 April 2018.
  7. ^ a b c d e Parks, Jake (2 April 2018). "Hubble spots farthest star ever seen". Astronomy. Retrieved 2 April 2018.
  8. ^ a b c Dunham, Will (2 April 2018). "Most distant star ever detected sits halfway across the universe". Reuters. Retrieved 3 April 2018.
  9. ^ a b c d Diego, J.M.; et al. (2 April 2018). "Dark Matter Under the Microscope: Constraining compact dark matter with caustic crossing events". The Astrophysical Journal. 857 (1): 25. arXiv:1706.10281. Bibcode:2018ApJ...857...25D. doi:10.3847/1538-4357/aab617. S2CID 55811307.
  10. ^ "Hubble uses cosmic lens to discover most distant star ever observed". Hubble Space Telescope. 2 April 2018. Retrieved 3 April 2018.
  11. ^ a b Guarino, Ben (3 April 2018). "This star is the farthest ever seen. It's 9 billion light-years away". The Washington Post.
  12. ^ a b Rosanne Di Stefano (2 April 2018). "Cosmic flashing lights". Nature Astronomy. Retrieved 6 April 2018.
  13. ^ S. A. Rodney; et al. (2 April 2018). "Two peculiar fast transients in a strongly lensed host galaxy". Nature Astronomy. 2 (4): 324–333. arXiv:1707.02434. Bibcode:2018NatAs...2..324R. doi:10.1038/s41550-018-0405-4. S2CID 119369406.

External links

Media files used on this page

Earth-moon.jpg
This view of the rising Earth greeted the Apollo 8 astronauts as they came from behind the Moon after the fourth nearside orbit. Earth is about five degrees above the horizon in the photo. The unnamed surface features in the foreground are near the eastern limb of the Moon as viewed from Earth. The lunar horizon is approximately 780 kilometers from the spacecraft. Width of the photographed area at the horizon is about 175 kilometers. On the Earth 240,000 miles away, the sunset terminator bisects Africa.
Crab Nebula.jpg
This is a mosaic image, one of the largest ever taken by NASA's Hubble Space Telescope, of the Crab Nebula, a six-light-year-wide expanding remnant of a star's supernova explosion. Japanese and Chinese astronomers recorded this violent event in 1054 CE, as did, almost certainly, Native Americans.

The orange filaments are the tattered remains of the star and consist mostly of hydrogen. The rapidly spinning neutron star embedded in the center of the nebula is the dynamo powering the nebula's eerie interior bluish glow. The blue light comes from electrons whirling at nearly the speed of light around magnetic field lines from the neutron star. The neutron star, like a lighthouse, ejects twin beams of radiation that appear to pulse 30 times a second due to the neutron star's rotation. A neutron star is the crushed ultra-dense core of the exploded star.

The Crab Nebula derived its name from its appearance in a drawing made by Irish astronomer Lord Rosse in 1844, using a 36-inch telescope. When viewed by Hubble, as well as by large ground-based telescopes such as the European Southern Observatory's Very Large Telescope, the Crab Nebula takes on a more detailed appearance that yields clues into the spectacular demise of a star, 6,500 light-years away.

The newly composed image was assembled from 24 individual Wide Field and Planetary Camera 2 exposures taken in October 1999, January 2000, and December 2000. The colors in the image indicate the different elements that were expelled during the explosion. Blue in the filaments in the outer part of the nebula represents neutral oxygen, green is singly-ionized sulfur, and red indicates doubly-ionized oxygen.
He1523a.jpg
Author/Creator: ESO, European Southern Observatory, Licence: CC BY 4.0
Artist's impression of "the oldest star of our Galaxy": HE 1523-0901
  • About 13.2 billion years old
  • Approximately 7500 light years far from Earth
  • Published as part of Hamburg/ESO Survey in the May 10 2007 issue of The Astrophysical Journal
NASA-Icarus-BlueSuperGiantSpectrum-Hubble-20180402.png
Comparison of Icarus Spectrum with Model of a Blue Supergiant Star Spectrum

https://www.nasa.gov/feature/goddard/2018/hubble-uncovers-the-farthest-star-ever-seen

Scientists found that the Hubble data from MACS J1149+2223 Lensed Star 1 (Icarus) matches the model for a blue supergiant. The agreement shows a remarkably good fit, and indicates that Icarus is approximately twice as hot as the Sun. The solid blue line shows the model spectrum of the blue supergiant, adjusted for the distance to the host galaxy of the highly magnified star. The red diamonds are the actual data measured for Icarus. The observed wavelength of the Balmer discontinuity relative to its intrinsic wavelength (at about 365 nm) is an indicator of the distance to the star. The strength of the Balmer discontinuity depends on the strength of the star's gravity at its surface and its temperature.
PIA22876-InSight-FirstSelfie-20181211.jpg
PIA22876: InSight's First Selfie

https://photojournal.jpl.nasa.gov/catalog/PIA22876

This is NASA InSight's first full selfie on Mars. It displays the lander's solar panels and deck. On top of the deck are its science instruments, weather sensor booms and UHF antenna.

The selfie is made up of 11 images which were taken by its Instrument Deployment Camera, located on the elbow of its robotic arm. Those images are then stitched together into a mosaic.

JPL manages InSight for NASA's Science Mission Directorate. InSight is part of NASA's Discovery Program, managed by the agency's Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.

A number of European partners, including France's Centre National d'Études Spatiales (CNES) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES and the Institut de Physique du Globe de Paris (IPGP) provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Institute of Technology (ETH) in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain's Centro de Astrobiología (CAB) supplied the wind sensors.

For more information about the mission, go to https://mars.nasa.gov/insight.
NASA-Icarus-MostDistantMainSequenceStar-20180402.jpg
Detection of Star Icarus (formally, MACS J1149 Lensed Star 1)

http://news.berkeley.edu/2018/04/02/cosmic-lens-helps-hubble-capture-most-distant-star-ever-seen/

A massive cluster (left) magnified a distant star more than 2,000 times, making it visible from Earth (lower right) even though it is 9 billion light years away, far too distant to be seen individually with current telescopes. It was not visible in 2011 (upper right).
Bennu at 300 pixels (wide).png
This view of asteroid 101955 Bennu has been cropped from the original image. Original Description: NASA’s OSIRIS-REx spacecraft obtained this image of the asteroid Bennu on November 16, 2018, from a distance of 85 miles (136 km). The image, which was taken by the PolyCam camera, shows Bennu at 300 pixels and has been stretched to increase contrast between highlights and shadows.