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 31
[2]
R Leporis: A Vampire's Star
Image Credit & Copyright [3] : Martin Pugh [4]
Explanation: Better known as Hind's Crimson Star [5] , R Leporis is a rare
star in planet Earth's night sky. It's also a shocking shade of red. The
star's discoverer, 19th century English astronomer John Russell Hind [6] ,
reported that it appeared in a telescope "... like a drop of blood on a black
field." Located [7] 1,360 light-years away in the constellation Lepus [8] the
star is a Mira-type [9] variable, changing its brightness over a period of
about 14 months. R Leporis is now recognized as a carbon star [10] , a very
cool and highly evolved red giant [11] with an extreme abundance of carbon.
Extra carbon in carbon stars is created by helium fusion [12] near the dying
stellar core and dredged up into the stars' outer layers. The dredge-up
results in an overabundance of simple carbon molecules, like CO, CH, CN, and
C2. While it's true [13] that cool stars radiate most of their energy in red
and infrared light, the carbon molecules strongly absorb what little blue
light is left and give carbon stars an exceptionally deep red color. R Leporis
is losing its carbon-rich atmosphere into the surrounding interstellar
material through a strong stellar wind though, and could be near the
transition to a planetary nebula [14] . Oh, and Happy Halloween [15] from the
folks at APOD.
Tomorrow's picture: ghost of long-dead star
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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]
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Site notes:
[1] archivepix.html
[2] image/1811/RLeporisMP.jpg
[3] lib/about_apod.html#srapply
[4] https://www.martinpughastrophotography.space/
[5] http://stars.astro.illinois.edu/sow/hinds.htm...
[6] https://en.wikipedia.org/wiki/John_Russell_Hi...
[7] http://simbad.harvard.edu/simbad/
sim-basic?Ident=R+Lep&submit=SIMBAD+search
[8] https://oneminuteastronomer.com/1206/vampire-...
[9] ap060722.html
[10] https://en.wikipedia.org/wiki/Carbon_star
[11] https://en.wikipedia.org/wiki/Red_giant
[12] https://en.wikipedia.org/wiki/Triple-alpha_pr...
[13] https://www.nasa.gov/image-feature/goddard/20...
hubble-views-striking-carbon-star-in-colorful-cluster
[14] ap181020.html
[15] ap161030.html
[16] ap181030.html
[17] archivepix.html
[18] lib/apsubmit2015.html
[19] lib/aptree.html
[20] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apo...
[21] calendar/allyears.html
[22] /apod.rss
[23] lib/edlinks.html
[24] lib/about_apod.html
[25] http://asterisk.apod.com/discuss_apod.php?dat...
[26] ap181101.html
[27] http://www.phy.mtu.edu/faculty/Nemiroff.html
[28] http://www.phy.mtu.edu/
[29] https://antwrp.gsfc.nasa.gov/htmltest/jbonnel...
[30] http://www.astro.umd.edu/
[31] lib/about_apod.html#srapply
[32] https://www.nasa.gov/about/highlights/HP_Priv...
[33] https://astrophysics.gsfc.nasa.gov/
[34] https://www.nasa.gov/
[35] https://www.nasa.gov/centers/goddard/
[36] http://www.mtu.edu/
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