Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble uses cosmic lens to discover most distant star ever observed

03.04.2018

Astronomers using the NASA/ESA Hubble Space Telescope have found the most distant star ever discovered. The hot blue star existed only 4.4 billion years after the Big Bang. This discovery provides new insight into the formation and evolution of stars in the early Universe, the constituents of galaxy clusters and also on the nature of dark matter.

The international team, led by Patrick Kelly (University of Minnesota, USA), Jose Diego (Instituto de Física de Cantabria, Spain) and Steven Rodney (University of South Carolina, USA), discovered the distant star in the galaxy cluster MACS J1149-2223 in April 2016. The observations with Hubble were actually performed in order to detect and follow the latest appearance of the gravitationally lensed supernova explosion nicknamed "Refsdal" (heic1525)[1], when an unexpected point source brightened in the same galaxy that hosted the supernova.


This image composite shows the discovery of the most distant known star using the NASA/ESA Hubble Space Telescope.

The image to the left shows a part of the the deep-field observation of the galaxy cluster MACS J1149.5+2223 from the Frontier Fields program gathered in 2014. The square indicates the position where the star appeared in May 2016 -- its image magnified by gravitational microlensing. This part of the image also shows the four images of the Refsdal supernova, arranged in an Einstein cross.

The upper right image pinpoints the position of the star, observed in 2011.

The lower right image shows where the star was undergoing the microlensing event in late May 2016.

Credit: NASA & ESA and P. Kelly (University of California, Berkeley)

"Like the Refsdal supernova explosion the light of this distant star got magnified, making it visible for Hubble," says Patrick Kelly. "This star is at least 100 times farther away than the next individual star we can study, except for supernova explosions."

The observed light from the newly discovered star, called Lensed Star 1 (LS1) was emitted when the Universe was only about 30 percent of its current age -- about 4.4 billion years after the Big Bang. The detection of the star through Hubble was only possible because the light from the star was magnified 2000 times.

"The star became bright enough to be visible for Hubble thanks to a process called gravitational lensing," explains Jose Diego. The light from LS1 was magnified not only by the huge total mass of the galaxy cluster, but also by another compact object of about three times the mass of the Sun within the galaxy cluster itself; an effect known as gravitational microlensing [2].

"The discovery of LS1 allows us to gather new insights into the constituents of the galaxy cluster. We know that the microlensing was caused by either a star, a neutron star, or a stellar-mass black hole," explains Steven Rodney. LS1 therefore allows astronomers to study neutron stars and black holes, which are otherwise invisible and they can estimate how many of these dark objects exist within this galaxy cluster.

As galaxy clusters are among the largest and most massive structures in the Universe, learning about their constituents also increases our knowledge about the composition of the Universe overall. This includes additional information about the mysterious dark matter.

"If dark matter is at least partially made up of comparatively low-mass black holes, as it was recently proposed, we should be able to see this in the light curve of LS1. Our observations do not favour the possibility that a high fraction of dark matter is made of these primordial black holes with about 30 times the mass of the Sun", highlights Kelly.

After the discovery the researchers used Hubble again to measure a spectrum of LS1. Based on their analysis, the astronomers think that LS1 is a B-type supergiant star. These stars are extremely luminous and blue in colour, with a surface temperature between 11 000 and 14 000 degrees Celsius; making them more than twice as hot as the Sun.

But this was not the end of the story. Observations made in October 2016 suddenly showed a second image of the star. "We were actually surprised to not have seen this second image in earlier observations, as also the galaxy the star is located in can be seen twice," comments Diego. "We assume that the light from the second image has been deflected by another moving massive object for a long time -- basically hiding the image from us. And only when the massive object moved out of the line of sight the second image of the star became visible." This second image and the blocking object add another piece of the puzzle to reveal the makeup of galaxy clusters.

With more research and the imminent arrival of new, more powerful telescopes like the NASA/ESA/CSA James Webb Space Telescope, the astronomers suggest that with microlensing, it will be possible to study the evolution of the earliest stars in the Universe in greater detail than ever expected.

###

Notes

[1] Observations of this supernova, nicknamed Refsdal in honour of the Norwegian astronomer Sjur Refsdal, were made as part of Hubble's Frontier Fields project.

[2] Gravitational lensing magnifies the light from fainter, background objects, allowing Hubble to see objects it would otherwise not be able to detect. The process was first predicted by Albert Einstein and is now used to find some of the most distant objects in the Universe. Usually the lensing object is a galaxy or a galaxy cluster, but in some cases it can also be a star or even a planet. When it involves these smaller objects the process is called microlensing.

More information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The results were released in the paper Extreme magnification of an individual star at redshift 1.5 by a galaxy-cluster lens to be published in Nature Astronomy.

The international team of astronomers in this study consists of P. Kelly (University of Minnesota, USA); J. Diego (IFAC, Instituto de F ísica de Cantabria, Spain); S. Rodney (University of South Carolina, USA); N. Kaiser (Institute for Astronomy, University of Hawaii, USA); T. Broadhurst (University of Basque Country, Spain and IKERBASQUE of the Basque Foundation for Science, Spain); A. Zitrin (Ben Gurion University of the Negev, Israel); T. Treu (University of California, Los Angeles, USA); P. Pérez-González (Universidad Complutense de Madrid, Spain); T. Morishita (University of California, Los Angeles, USA; Tohoku University, Japan) M. Jauzac (Durham University, U.K.; University of KwaZulu-Natal, South Africa); J. Selsing (University of Copenhagen, Denmark); M. Oguri (University of Tokyo, Japan); L. Pueyo (Space Telescope Science Institute, USA); T. W. Ross (University of California, Berkeley, USA); A. V. Filippenko (University of California, Berkeley, USA); N. Smith (University of Arizona, USA); J. Hjorth (University of Copenhagen, Denmark); S. B. Cenko (Goddard Space Flight Center, USA; University of Maryland, USA); Xin Wang (University of California, Los Angeles, USA); D. A. Howell (Las Cumbres Observatory, USA; University of California, Santa Barbara, USA); J. Richard (Université Claude Bernard Lyon 1, France); B. L. Frye (University of Arizona, USA); S. W. Jha (The State University of New Jersey, USA); R.J. Foley (University of California, Santa Cruz); C. Norman (the Johns Hopkins University, USA); M. Bradac (University of California, Davis, USA); WeiKang Zheng (University of California, Berkeley, USA); G. Brammer (Space Telescope Science Institute, USA); A. M. Benito (Universidade de São Paulo); A. Cava (University of Geneva, Switzerland); L. Christensen (University of Copenhagen, Denmark); S. D de Mink (University of Amsterdam, the Netherlands); Or Gaur (Harvard-Smithsonian Center for Astrophysics, USA; American Museum of Natural History, USA; NSF Astronomy and Astrophysics Postdoctoral Fellow); C. Grillo (Universitá degli Studi di Milano, Italy); R. Kawamata (University of Tokyo, Japan); J. Kneib (Observatoire de Sauverny, Switzerland); T. Matheson (National Optical Astronomical Observatory, USA); C. McCully (Las Cubres Observatory, USA; University of California, Santa Barbara); M. Nonino (Osservatorio Astronomico di Trieste, Italy); I. Perez-Fournon (Instituto de Astrofísica de Canarias, Spain; Universidad de La Laguna, Spain); A. G. Reiss (The Johns Hopkins University, USA; Space Telescope Science Institute, USA); P. Rosati (Universitá degli Studi di Ferrara, Italy); K. Borello Schmidt (Leibniz-Institut für Astrophysik Potsdam, Germany); K. Sharon (University of Michigan, USA); and B. J. Weiner (University of Arizona, USA)

Links

* Images of Hubble - http://www.spacetelescope.org/images/archive/category/spacecraft/

* Hubblesite release - http://hubblesite.org/news_release/news/2017-34

* Science paper - http://www.spacetelescope.org/static/archives/releases/science_papers/heic1807/heic1807a.pdf

Contacts

Patrick Kelly
University of Minnesota, Twin Cities
Minneapolis, USA
Email: plkelly@umn.edu

Jose M. Diego
Instituto de Física de Cantabria
Santander, Spain
Tel: +34 942201452
Email: jdiego@ifca.unican.es

Steven Rodney
University of South Carolina
Columbia, USA
Email: srodney@sc.edu

Mathias Jäger
ESA/Hubble, Public Information Officer
Garching bei München, Germany
Tel: +49 176 62397500
Email: mjaeger@partner.eso.org

http://www.spacetelescope.org 

Mathias Jäger | EurekAlert!
Further information:
https://www.spacetelescope.org/news/heic1807/

Further reports about: ESA Hubble Space Telescope cosmic lens galaxy cluster

More articles from Physics and Astronomy:

nachricht Researchers discover link between magnetic field strength and temperature
21.08.2018 | American Institute of Physics

nachricht Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Air pollution leads to cardiovascular diseases

21.08.2018 | Ecology, The Environment and Conservation

Researchers target protein that protects bacteria's DNA 'recipes'

21.08.2018 | Life Sciences

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>