Subj : Daily APOD Report To : All From : Ben Ritchey Date : Thu Apr 11 2019 08:43:42 Astronomy Picture of the Day Astronomy Picture of the Day Discover the cosmos! [1] Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2019 April 11 [2] First Horizon-Scale Image of a Black Hole Image Credit: Event Horizon Telescope [3] Collaboration [4] Explanation: What does a black hole look like? To find out, radio telescopes [5] from around the Earth [6] coordinated observations of black holes [7] with the largest known event horizon [8] s on the sky. Alone, black holes are just black [9] , but these monster attractors are known to be surrounded by glowing gas. The first image was released yesterday and resolved [10] the area around the black hole [11] at the center of galaxy M87 [12] on a scale below that expected for its event horizon [13] . Pictured [14] , the dark central region is not the event horizon, but rather the black hole's shadow [15] -- the central region of emitting gas darkened by the central black hole's gravity. The size and shape of the shadow is determined by bright gas near the event horizon [16] , by strong gravitational lensing deflections [17] , and by the black hole's spin. In resolving this black hole's shadow [18] , the Event Horizon Telescope [19] (ETH) bolstered evidence that Einstein's gravity [20] works even in extreme regions [21] , and gave clear evidence that M87 [22] has a central spinning black hole of about 6 billion solar masses. The EHT [23] is not done -- future observations will be geared toward even higher resolution [24] , better tracking of variability, and exploring the immediate vicinity of the (link)black hole in the center [25] of our Milky Way Galaxy [26] . Tomorrow's picture: open space ------------------------------------------------------------------------------- < [27] | Archive [28] | Submissions [29] | Index [30] | Search [31] | Calendar [32] | RSS [33] | Education [34] | About APOD [35] | Discuss [36] | > [37] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [38] (MTU [39] ) & Jerry Bonnell [40] (UMCP [41] ) NASA Official: Phillip Newman Specific rights apply [42] . NASA Web Privacy Policy and Important Notices [43] A service of: ASD [44] at NASA [45] / GSFC [46] & Michigan Tech. U. [47] ---------- Site notes: [1] archivepix.html [2] image/1904/M87bh_EHT_2629.jpg [3] https://eventhorizontelescope.org/ [4] https://eventhorizontelescope.org/organization [5] https://en.wikipedia.org/wiki/Radio_telescope [6] https://iopscience-event-horizon.s3.amazonaws.com/journal/2041-8205/page/img/ focus_figure_2_resized.jpg [7] https://science.nasa.gov/astrophysics/focus-areas/black-holes [8] https://en.wikipedia.org/wiki/Event_horizon#Event_horizon_of_a_black_hole [9] https://en.wikipedia.org/wiki/Black [10] https://www.eso.org/public/usa/outreach/first-picture-of-a-black-hole/blog/ [11] https://www.nsf.gov/news/special_reports/blackholes/ [12] ap100520.html [13] https://www.forbes.com/sites/startswithabang/2019/04/10/ black-holes-are-real-and-spectacular-and-so-are-their-event-horizons/ [14] https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT [15] https://www.esa.int/gsp/ACT/projects/blackhole_shadows.html [16] https://www.youtube.com/watch?v=t-O-Qdh7VvQ [17] https://apod.nasa.gov/htmltest/rjn_bht.html [18] https://iopscience.iop.org/article/10.3847/2041-8213/ab0ec7 [19] https://eventhorizontelescope.org/about [20] https://en.wikipedia.org/wiki/General_relativity [21] https://youtu.be/bciCbN8lc08 [22] http://chandra.si.edu/photo/2019/black_hole/ [23] https://eventhorizontelescope.org/ [24] https://previews.123rf.com/images/aleksandrrr/aleksandrrr1606/ aleksandrrr160600010/60185350-gray-kitten-and-microscope.jpg [25] ap180729.html [26] https://solarsystem.nasa.gov/resources/285/the-milky-way-galaxy/ [27] ap190410.html [28] archivepix.html [29] lib/apsubmit2015.html [30] lib/aptree.html [31] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [32] calendar/allyears.html [33] /apod.rss [34] lib/edlinks.html [35] lib/about_apod.html [36] http://asterisk.apod.com/discuss_apod.php?date=190411 [37] ap190412.html [38] http://www.phy.mtu.edu/faculty/Nemiroff.html [39] http://www.phy.mtu.edu/ [40] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [41] http://www.astro.umd.edu/ [42] lib/about_apod.html#srapply [43] https://www.nasa.gov/about/highlights/HP_Privacy.html [44] https://astrophysics.gsfc.nasa.gov/ [45] https://www.nasa.gov/ [46] https://www.nasa.gov/centers/goddard/ [47] http://www.mtu.edu/ --- Mystic BBS v1.12 A43 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .