Subj : Daily APOD Report To : All From : Ben Ritchey Date : Thu Feb 21 2019 08:25:00 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 February 21 [2] Reflections on vdB 9 Image Credit & Copyright [3] : Guenter Kerschhuber [4] Explanation: Centered in a well-composed celestial still life, pretty, blue vdB 9 is the 9th object [5] in Sidney van den Bergh's 1966 catalog [6] of reflection nebulae. It shares this telescopic field of view, about twice the size of a full moon on the sky, with stars and dark, obscuring dust clouds in the northerly constellation Cassiopeia. Cosmic dust is preferentially reflecting blue starlight from embedded, hot star SU Cassiopeiae [7] , giving vdB 9 the characteristic bluish tint associated with a classical reflection nebula. SU Cas is a Cepheid variable star, though even at its brightest it is just too faint to be seen with the unaided eye. Still Cepheids play an important role in determining distances in our galaxy and beyond [8] . At the star's well-known distance of 1,540 light-years, this cosmic canvas [9] would be about 24 light-years across. Tomorrow's picture: pixels in space ------------------------------------------------------------------------------- < [10] | Archive [11] | Submissions [12] | Index [13] | Search [14] | Calendar [15] | RSS [16] | Education [17] | About APOD [18] | Discuss [19] | > [20] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [21] (MTU [22] ) & Jerry Bonnell [23] (UMCP [24] ) NASA Official: Phillip Newman Specific rights apply [25] . NASA Web Privacy Policy and Important Notices [26] A service of: ASD [27] at NASA [28] / GSFC [29] & Michigan Tech. U. [30] ---------- Site notes: [1] archivepix.html [2] image/1902/20181013VDB9kerschhuber.jpg [3] lib/about_apod.html#srapply [4] http://kerschhuber.astronomie.at/index.html [5] ap121026.html [6] http://adsabs.harvard.edu/abs/1966AJ.....71..990V [7] http://simbad.harvard.edu/simbad/ sim-basic?Ident=vdb+9&submit=SIMBAD+search [8] http://heritage.stsci.edu/2011/15/caption.html [9] http://kerschhuber.astronomie.at/Nebula/slides/VDB9.html [10] ap190220.html [11] archivepix.html [12] lib/apsubmit2015.html [13] lib/aptree.html [14] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [15] calendar/allyears.html [16] /apod.rss [17] lib/edlinks.html [18] lib/about_apod.html [19] http://asterisk.apod.com/discuss_apod.php?date=190221 [20] ap190222.html [21] http://www.phy.mtu.edu/faculty/Nemiroff.html [22] http://www.phy.mtu.edu/ [23] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [24] http://www.astro.umd.edu/ [25] lib/about_apod.html#srapply [26] https://www.nasa.gov/about/highlights/HP_Privacy.html [27] https://astrophysics.gsfc.nasa.gov/ [28] https://www.nasa.gov/ [29] https://www.nasa.gov/centers/goddard/ [30] http://www.mtu.edu/ --- Mystic BBS v1.12 A43 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .