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. 2023 July 7 [2]See Explanation. Clicking on the picture will download the highest resolution version available. The Double Cluster in Perseus Image Credit & [3]Copyright: [4]Mårten Frosth Explanation: [5]This pretty starfield spans about three full moons (1.5 degrees) across the heroic northern constellation of [6]Perseus. It holds the famous [7]pair of open star clusters, h and Chi Persei. Also cataloged as [8]NGC 869 (top) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. Separated by only a few hundred light-years, the clusters are both 13 million years young [9]based on the ages of their [10]individual stars, evidence that they were likely a product of the same star-forming region. Always a rewarding [11]sight in binoculars, the Double Cluster is even visible to the unaided eye from [12]dark locations. Tomorrow's picture: light-weekend __________________________________________________________________ [13]< | [14]Archive | [15]Submissions | [16]Index | [17]Search | [18]Calendar | [19]RSS | [20]Education | [21]About APOD | [22]Discuss | [23]> __________________________________________________________________ Authors & editors: [24]Robert Nemiroff ([25]MTU) & [26]Jerry Bonnell ([27]UMCP) NASA Official: Phillip Newman [28]Specific rights apply. [29]NASA Web Privacy Policy and Important Notices A service of: [30]ASD at [31]NASA / [32]GSFC & [33]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2307/Caldwell_14_2023_HaLRGB_LRGB_stars_wm.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://www.frosth.se/ 5. https://www.frosth.se/2023/05/07/caldwell-14-double-cluster/ 6. http://en.wikipedia.org/wiki/Perseus_constellation 7. https://www.nasa.gov/feature/goddard/caldwell-14 8. http://www.messier.seds.org/xtra/ngc/n0869.html 9. http://arxiv.org/abs/astro-ph/0205130 10. http://www.messier.seds.org/open.html 11. http://10minuteastronomy.wordpress.com/2009/11/21/mission-11-cassiopeia-and-the-double-cluster/ 12. https://apod.nasa.gov/apod/ap060413.html 13. https://apod.nasa.gov/apod/ap230706.html 14. https://apod.nasa.gov/apod/archivepix.html 15. https://apod.nasa.gov/apod/lib/apsubmit2015.html 16. https://apod.nasa.gov/apod/lib/aptree.html 17. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 18. https://apod.nasa.gov/apod/calendar/allyears.html 19. https://apod.nasa.gov/apod.rss 20. https://apod.nasa.gov/apod/lib/edlinks.html 21. https://apod.nasa.gov/apod/lib/about_apod.html 22. http://asterisk.apod.com/discuss_apod.php?date=230707 23. https://apod.nasa.gov/apod/ap230708.html 24. http://www.phy.mtu.edu/faculty/Nemiroff.html 25. http://www.phy.mtu.edu/ 26. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 27. http://www.astro.umd.edu/ 28. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 29. https://www.nasa.gov/about/highlights/HP_Privacy.html 30. https://astrophysics.gsfc.nasa.gov/ 31. https://www.nasa.gov/ 32. https://www.nasa.gov/centers/goddard/ 33. http://www.mtu.edu/