Subj : Daily APOD Report To : All From : Ben Ritchey Date : Sat Oct 20 2018 07:51:45 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 October 20 [2] Halo of the Cat's Eye Image Credit & Copyright [3] : Data: Michael Joner (West Mountain Observatory [4] , BYU), Romano Corradi [5] (IAC [6] ), Hubble Legacy Archive [7] - Processing: Robert Gendler [8] Explanation: Not a Falcon 9 [9] rocket launch after sunset, the Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries [10] are seen in the very central region of this composited picture [11] , processed to reveal an enormous but extremely faint halo of gaseous material, over three light-years across. Made with data from ground- and space-based telescopes it shows the extended emission which surrounds the brighter, familiar planetary nebula [12] . Planetary nebulae have long been appreciated as a final phase in the life [13] of a sun-like star. But only more recently have some planetaries been found to have halos [14] like this one, likely formed of material shrugged off during earlier active episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the outer filamentary portions [15] of this halo to be 50,000 to 90,000 years old. Tomorrow's picture: meteor, comet, nebula ------------------------------------------------------------------------------- < [16] | Archive [17] | Submissions [18] | Index [19] | Search [20] | Calendar [21] | RSS [22] | Education [23] | About APOD [24] | Discuss [25] | > [26] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [27] (MTU [28] ) & Jerry Bonnell [29] (UMCP [30] ) NASA Official: Phillip Newman Specific rights apply [31] . NASA Web Privacy Policy and Important Notices [32] A service of: ASD [33] at NASA [34] / GSFC [35] & Michigan Tech. U. [36] ---------- Site notes: [1] archivepix.html [2] image/1810/NGC6543-BYU-L.jpg [3] lib/about_apod.html#srapply [4] http://wmo.byu.edu/ [5] http://vivaldi.ll.iac.es/galeria/rcorradi/ [6] http://www.iac.es/ [7] http://hla.stsci.edu/ [8] http://www.robgendlerastropics.com/ [9] ap181012.html [10] ap080804.html [11] http://www.robgendlerastropics.com/NGC6543-BYU.html [12] http://en.wikipedia.org/wiki/Planetary_nebula [13] https://imagine.gsfc.nasa.gov/educators/lifecycles/stars.html [14] ap140522.html [15] http://www.youtube.com/watch?v=tw0VJ1K93PM [16] ap181019.html [17] archivepix.html [18] lib/apsubmit2015.html [19] lib/aptree.html [20] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [21] calendar/allyears.html [22] /apod.rss [23] lib/edlinks.html [24] lib/about_apod.html [25] http://asterisk.apod.com/discuss_apod.php?date=181020 [26] ap181021.html [27] http://www.phy.mtu.edu/faculty/Nemiroff.html [28] http://www.phy.mtu.edu/ [29] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [30] http://www.astro.umd.edu/ [31] lib/about_apod.html#srapply [32] https://www.nasa.gov/about/highlights/HP_Privacy.html [33] https://astrophysics.gsfc.nasa.gov/ [34] https://www.nasa.gov/ [35] https://www.nasa.gov/centers/goddard/ [36] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .