Mosaic of Gravitationally Lensed Quasars: Each of these Hubble Space Telescope snapshots reveals four distorted images of a background quasar surrounding the central core of a foreground massive galaxy. The multiple quasar images were produced by the gravity of the foreground galaxy, which is acting like a magnifying glass by warping the quasar’s light in an effect called gravitational lensing. Quasars are extremely distant cosmic streetlights produced by active black holes. The light rays from each lensed quasar image take a slightly different path through space to reach Earth. The pathway’s length depends on the amount of matter that is distorting space along the line of sight to the quasar. To trace each pathway, the astronomers monitor the flickering of the quasar’s light as its black hole gobbles up material. When the light flickers, each lensed image brightens at a different time. This flickering sequence allows researchers to measure the time delays between each image as the lensed light travels along its path to Earth. These time-delay measurements helped astronomers calculate how fast the universe is growing, a value called the Hubble constant. The Hubble images were taken between 2003 and 2004 with the Advanced Camera for Surveys.

Type: Early Universe : Galaxy : Activity : AGN : Quasar
Category: Cosmology
Release date: 13 January 2020, 10:12
Credit: NASA, ESA, S.H. Suyu (Max Planck Institute for Astrophysics, Technical University of Munich, and Academia Sinica Institute of Astronomy and Astrophysics), and K.C. Wong (University of Tokyo’s Kavli Institute for the Physics and Mathematics of the Universe)

Quasars' Multiple Images Shed Light on Tiny Dark Matter Clumps: Each of these Hubble Space Telescope snapshots reveals four distorted images of a background quasar and its host galaxy surrounding the central core of a foreground massive galaxy. The gravity of the massive foreground galaxy is acting like a magnifying glass by warping the quasar’s light in an effect called gravitational lensing. Quasars are extremely distant cosmic streetlights produced by active black holes. Such quadruple images of quasars are rare because of the nearly exact alignment needed between the foreground galaxy and background quasar. Astronomers used the gravitational lensing effect to detect the smallest clumps of dark matter ever found. The clumps are located along the telescope's line of sight to the quasars, as well as in and around the foreground lensing galaxies. The presence of the dark matter concentrations alters the apparent brightness and position of each distorted quasar image. Astronomers compared these measurements with predictions of how the quasar images would look without the influence of the dark matter clumps. The researchers used these measurements to calculate the masses of the tiny dark matter concentrations. Hubble's Wide Field Camera 3 captured the near-infrared light from each quasar and dispersed it into its component colors for study with spectroscopy. The images were taken between 2015 and 2018.

Type: Early Universe : Galaxy : Type : Gravitationally LensedEarly Universe : Cosmology : Phenomenon : Lensing
Category: Cosmology
Release date: 13 January 2020, 10:11
Credit: NASA, ESA, A. Nierenberg (JPL) and T. Treu (UCLA)

Hubble Probes Goldilocks Stars: This infographic compares the characteristics of three classes of stars in our galaxy: Sunlike stars are classified as G stars; stars less massive and cooler than our Sun are K dwarfs; and even fainter and cooler stars are the reddish M dwarfs. The graphic compares the stars in terms of several important variables. The habitable zones, potentially capable of hosting life-bearing planets, are wider for hotter stars. The longevity for red dwarf M stars can exceed 100 billion years. K dwarf ages can range from 15 to 45 billion years. And, our Sun only lasts for 10 billion years. The relative amount of harmful radiation (to life as we know it) that stars emit can be 80 to 500 times more intense for M dwarfs relative to our Sun, but only 5 to 25 times more intense for the orange K dwarfs. Red dwarfs make up the bulk of the Milky Way's population, about 73%. Sunlike stars are merely 6% of the population, and K dwarfs are at 13%. When these four variables are balanced, the most suitable stars, for potentially hosting advanced life forms are K dwarfs, sometimes called Goldilocks Stars In a program called the "GoldiloKs" Project, Edward Guinan of Villanova University, Villanova, Pennsylvania, USA and his Villanova colleague Scott Engle, working with undergraduate students, measured the age, rotation rate, and X-ray and far-ultraviolet radiation in a sampling of mostly cool G and K stars. They are using the NASA/ESA Hubble Space Telescope and the European Space Agency's XMM-Newton satellite. Hubble's sensitive ultraviolet-light observations of radiation from hydrogen were used to assess the radiation from a sample of about 20 orange dwarfs. The results were presented at the 235th meeting of the American Astronomical Society in Honolulu, Hawaii. Link:

Type: Milky Way : Star
Category: Stars
Release date: 13 January 2020, 10:09
Credit: NASA, ESA, and Z. Levy (STScI)

Hubble Probes Goldilocks Stars: This infographic compares the characteristics of three classes of stars in our galaxy: Sunlike stars are classified as G stars; stars less massive and cooler than our Sun are K dwarfs; and even fainter and cooler stars are the reddish M dwarfs. The graphic compares the stars in terms of several important variables. The habitable zones, potentially capable of hosting life-bearing planets, are wider for hotter stars. The longevity for red dwarf M stars can exceed 100 billion years. K dwarf ages can range from 15 to 45 billion years. And, our Sun only lasts for 10 billion years. The relative amount of harmful radiation (to life as we know it) that stars emit can be 80 to 500 times more intense for M dwarfs relative to our Sun, but only 5 to 25 times more intense for the orange K dwarfs. Red dwarfs make up the bulk of the Milky Way's population, about 73%. Sunlike stars are merely 6% of the population, and K dwarfs are at 13%. When these four variables are balanced, the most suitable stars, for potentially hosting advanced life forms are K dwarfs, sometimes called Goldilocks Stars In a program called the "GoldiloKs" Project, Edward Guinan of Villanova University, Villanova, Pennsylvania, USA and his Villanova colleague Scott Engle, working with undergraduate students, measured the age, rotation rate, and X-ray and far-ultraviolet radiation in a sampling of mostly cool G and K stars. They are using the NASA/ESA Hubble Space Telescope and the European Space Agency's XMM-Newton satellite. Hubble's sensitive ultraviolet-light observations of radiation from hydrogen were used to assess the radiation from a sample of about 20 orange dwarfs. The results were presented at the 235th meeting of the American Astronomical Society in Honolulu, Hawaii. Link:

Type: Milky Way : Star
Category: Stars
Release date: 13 January 2020, 10:09
Credit: NASA, ESA, and Z. Levy (STScI)