Subj : Daily APOD Report To : All From : Ben Ritchey Date : Mon Aug 13 2018 11:27:58 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. 2018 August 13 [2] The Pencil Nebula in Red and Blue Image Credit & Copyright: José Joaquín Perez [3] Explanation: This shock wave plows through interstellar space at over 500,000 kilometers per hour. Near the top and moving up in this sharply detailed color composite, thin, bright, braided filaments are actually long ripples in a cosmic sheet of glowing gas seen almost edge-on. Cataloged as NGC 2736 [4] , its elongated appearance suggests its popular name, the Pencil Nebula [5] . The Pencil Nebula [6] is about 5 light-years long and 800 light-years [7] away, but represents only a small part of the Vela supernova remnant [8] . The Vela remnant itself [9] is around 100 light-years in diameter, the expanding debris cloud of a star [10] that was seen to explode [11] about 11,000 years ago. Initially, the shock wave [12] was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. In the featured narrow-band, wide field image, red and blue colors track the characteristic glow of ionized hydrogen [13] and oxygen atoms [14] , respectively. Growing Galleries: Launch of the Parker Solar Probe [15] and Perseid Meteor Shower 2018 [16] Tomorrow's picture: of gas and galaxies ------------------------------------------------------------------------------- < [17] | Archive [18] | Submissions [19] | Index [20] | Search [21] | Calendar [22] | RSS [23] | Education [24] | About APOD [25] | Discuss [26] | > [27] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [28] (MTU [29] ) & Jerry Bonnell [30] (UMCP [31] ) NASA Official: Phillip Newman Specific rights apply [32] . NASA Web Privacy Policy and Important Notices [33] A service of: ASD [34] at NASA [35] / GSFC [36] & Michigan Tech. U. [37] ---------- Site notes: [1] archivepix.html [2] image/1808/PencilNebula_Perez_1553.jpg [3] http://www.astro-austral.cl/aboutme.htm [4] http://heritage.stsci.edu/2003/16/supplemental.html [5] http://www.nasa.gov/vision/universe/starsgalaxies/ pencil_nebula.html [6] https://www.youtube.com/watch?v=P4rXhOArFw8 [7] https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html [8] http://violet.pha.jhu.edu/~wpb/hstvela/hstvela.html [9] ap080306.html [10] http://chandra.harvard.edu/xray_sources/supernovas.html [11] ap131001.html [12] ap170408.html [13] http://astronomy.swin.edu.au/cosmos/i/ionised+hydrogen [14] https://periodic.lanl.gov/8.shtml [15] https://www.facebook.com/pg/APOD.Sky/photos/ ?tab=album&album_id=1543737952397085 [16] https://www.facebook.com/pg/APOD.Sky/photos/ ?tab=album&album_id=1543789772391903 [17] ap180812.html [18] archivepix.html [19] lib/apsubmit2015.html [20] lib/aptree.html [21] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [22] calendar/allyears.html [23] /apod.rss [24] lib/edlinks.html [25] lib/about_apod.html [26] http://asterisk.apod.com/discuss_apod.php?date=180813 [27] ap180814.html [28] http://www.phy.mtu.edu/faculty/Nemiroff.html [29] http://www.phy.mtu.edu/ [30] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [31] http://www.astro.umd.edu/ [32] lib/about_apod.html#srapply [33] https://www.nasa.gov/about/highlights/HP_Privacy.html [34] https://astrophysics.gsfc.nasa.gov/ [35] https://www.nasa.gov/ [36] https://www.nasa.gov/centers/goddard/ [37] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .