Astronomy Picture of the Day

   [1]Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                               2022 February 5
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                             Symbiotic R Aquarii
     Image Credit: X-ray: [3]NASA/[4]CXC/SAO/R. Montez et al.; Optical:
    Data: NASA/[5]ESA/[6]STScI, Processing: [7]Judy Schmidt (CC BY-NC-SA)

   Explanation: [8]Variable star R Aquarii is actually an interacting
   binary star system, [9]two stars that seem to have a close symbiotic
   relationship. Centered in this [10]space-based optical/x-ray composite
   image it lies about 710 light years away. The intriguing system
   consists of a cool [11]red giant star and hot, dense [12]white dwarf
   star in mutual orbit around their common center of mass. With
   binoculars you can watch as R Aquarii steadily changes its brightness
   over the course of a year or so. The binary system's visible light is
   dominated by the red giant, itself a [13]Mira-type long period
   [14]variable star. But material in the cool giant star's extended
   envelope is pulled by gravity onto the surface of the smaller, denser
   white dwarf, [15]eventually triggering a thermonuclear explosion,
   blasting material into space. Astronomers have seen such outbursts over
   recent decades. Evidence for much older outbursts is seen in [16]these
   spectacular structures spanning almost a light-year as observed by the
   Hubble Space Telescope (in red and blue). Data from the Chandra X-ray
   Observatory (in purple) shows the X-ray glow from shock waves created
   as a jet from the white dwarf strikes surrounding material.

                     Tomorrow's picture: our fair planet
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    Authors & editors: [28]Robert Nemiroff ([29]MTU) & [30]Jerry Bonnell
                                 ([31]UMCP)
          NASA Official: Phillip Newman [32]Specific rights apply.
              [33]NASA Web Privacy Policy and Important Notices
                A service of: [34]ASD at [35]NASA / [36]GSFC
                           & [37]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2202/archives_raquarii.jpg
   3. https://www.nasa.gov/
   4. https://chandra.harvard.edu/
   5. https://www.esa.int/
   6. https://www.stsci.edu/
   7. https://geckzilla.com/
   8. https://www.aavso.org/vsots_raqr
   9. http://chandra.harvard.edu/photo/2017/raqr/
  10. https://chandra.harvard.edu/photo/2022/archives/
  11. https://en.wikipedia.org/wiki/Red_giant
  12. https://imagine.gsfc.nasa.gov/science/objects/dwarfs2.html
  13. https://apod.nasa.gov/apod/ap060722.html
  14. https://www.aavso.org/public
  15. https://apod.nasa.gov/apod/ap060726.html
  16. https://www.nasa.gov/mission_pages/chandra/news/an-expanse-of-light.html
  17. https://apod.nasa.gov/apod/ap220204.html
  18. https://apod.nasa.gov/apod/archivepix.html
  19. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  20. https://apod.nasa.gov/apod/lib/aptree.html
  21. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  22. https://apod.nasa.gov/apod/calendar/allyears.html
  23. https://apod.nasa.gov/apod.rss
  24. https://apod.nasa.gov/apod/lib/edlinks.html
  25. https://apod.nasa.gov/apod/lib/about_apod.html
  26. http://asterisk.apod.com/discuss_apod.php?date=220205
  27. https://apod.nasa.gov/apod/ap220206.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. https://apod.nasa.gov/apod/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/