Subj : Daily APOD Report To : All From : Ben Ritchey Date : Wed Aug 01 2018 12:47:22 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 1 [2] The Iris Nebula in a Field of Dust Image Credit & Copyright: Franco Sgueglia & Francesco Sferlazza [3] Explanation: What blue flower grows in this field of dark interstellar dust? The Iris Nebula [4] . The striking blue color of the Iris Nebula [5] is created by light from the bright star SAO 19158 [6] reflecting off of a dense patch of normally dark dust [7] . Not only is the star itself mostly blue, but blue light from the star is preferentially reflected [8] by the dust -- the same affect that makes Earth's sky blue [9] . The brown tint of the pervasive dust comes partly from photoluminescence [10] -- dust converting ultraviolet radiation [11] to red [12] light. Cataloged as NGC [13] 7023, the Iris Nebula is studied [14] frequently because of the unusual prevalence there of Polycyclic Aromatic Hydrocarbons [15] (PAHs), complex molecules that are also released on Earth during the incomplete combustion of wood fires. The bright blue portion of the Iris Nebula [16] spans about six light years. The Iris [17] Nebula, pictured here, lies about 1300 light years distant and can be found [18] with a small telescope toward the constellation of Cepheus [19] . APOD Event: APOD Editor to speak at Fermilab on August 8 [20] Tomorrow's picture: lunar eclipse for poets ------------------------------------------------------------------------------- < [21] | Archive [22] | Submissions [23] | Index [24] | Search [25] | Calendar [26] | RSS [27] | Education [28] | About APOD [29] | Discuss [30] | > [31] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [32] (MTU [33] ) & Jerry Bonnell [34] (UMCP [35] ) NASA Official: Phillip Newman Specific rights apply [36] . NASA Web Privacy Policy and Important Notices [37] A service of: ASD [38] at NASA [39] / GSFC [40] & Michigan Tech. U. [41] ---------- Site notes: [1] archivepix.html [2] image/1808/IrisNebula_Sgueglia_2729.jpg [3] mailto: sferlazza @at@ gmail .dot. com [4] http://en.wikipedia.org/wiki/Iris_Nebula [5] ap101112.html [6] http://www.starrywonders.com/irisst8300.html [7] http://ned.ipac.caltech.edu/level5/Mathis/Mathis1.html [8] http://en.wikipedia.org/wiki/Reflection_nebula [9] http://spaceplace.nasa.gov/blue-sky/en/ [10] http://en.wikipedia.org/wiki/Photoluminescence [11] https://science.nasa.gov/ems/10_ultravioletwaves [12] http://upload.wikimedia.org/wikipedia/commons/2/25/Red.svg [13] http://en.wikipedia.org/wiki/List_of_NGC_objects [14] http://adsabs.harvard.edu/abs/2005A%26A...429..193R [15] http://www.chem.ucl.ac.uk/cosmicdust/pah.htm#what [16] ap051229.html [17] http://en.wikipedia.org/wiki/Iris_(plant) [18] https://www.youtube.com/watch?v=kV3L6tMkTCs [19] http://hawastsoc.org/deepsky/cep/index.html [20] https://www.facebook.com/events/224564531505324/ [21] ap180731.html [22] archivepix.html [23] lib/apsubmit2015.html [24] lib/aptree.html [25] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [26] calendar/allyears.html [27] /apod.rss [28] lib/edlinks.html [29] lib/about_apod.html [30] http://asterisk.apod.com/discuss_apod.php?date=180801 [31] ap180802.html [32] http://www.phy.mtu.edu/faculty/Nemiroff.html [33] http://www.phy.mtu.edu/ [34] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [35] http://www.astro.umd.edu/ [36] lib/about_apod.html#srapply [37] https://www.nasa.gov/about/highlights/HP_Privacy.html [38] https://astrophysics.gsfc.nasa.gov/ [39] https://www.nasa.gov/ [40] https://www.nasa.gov/centers/goddard/ [41] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .