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 February 23 [2]See Explanation. Clicking on the picture will download the highest resolution version available. Arp 78: Peculiar Galaxy in Aries Image Credit & [3]Copyright: [4]Josep Drudis Explanation: [5]Peculiar spiral galaxy Arp 78 is found within the boundaries of the head strong [6]constellation Aries. Some 100 million light-years beyond the stars and nebulae of our Milky Way galaxy, the island universe is an enormous 200,000 light-years across. [7]Also known as NGC 772, it sports a prominent, outer spiral arm in [8]this detailed cosmic portrait. Tracking along sweeping dust lanes and [9]lined with young blue star clusters, Arp 78's overdeveloped spiral arm is [10]pumped-up by galactic-scale gravitational tides. Interactions with its brightest companion galaxy, the more compact NGC 770 seen above and right of the larger spiral, are likely responsible. Embedded in faint star streams revealed in the deep telescopic exposure, NGC 770's fuzzy, elliptical appearance contrasts nicely with spiky foreground Milky Way stars in matching yellowish hues. Tomorrow's picture: beyond Jones-Emberson 1 __________________________________________________________________ [11]< | [12]Archive | [13]Submissions | [14]Index | [15]Search | [16]Calendar | [17]RSS | [18]Education | [19]About APOD | [20]Discuss | [21]> __________________________________________________________________ Authors & editors: [22]Robert Nemiroff ([23]MTU) & [24]Jerry Bonnell ([25]UMCP) NASA Official: Phillip Newman [26]Specific rights apply. [27]NASA Web Privacy Policy and Important Notices A service of: [28]ASD at [29]NASA / [30]GSFC, [31]NASA Science Activation & [32]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2302/NGC772-L2bh-RGB-19-8aT-cC.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. http://www.astrodrudis.com/ 5. http://ned.ipac.caltech.edu/level5/Arp/frames.html 6. http://hawastsoc.org/deepsky/ari/index.html 7. https://www.nasa.gov/image-feature/goddard/2019/hubble-spots-a-curious-spiral 8. https://astrodrudis.com/ngc-772-and-companions/ 9. http://arxiv.org/abs/0810.1748 10. https://noirlab.edu/public/images/noirlab2209a/ 11. https://apod.nasa.gov/apod/ap230222.html 12. https://apod.nasa.gov/apod/archivepix.html 13. https://apod.nasa.gov/apod/lib/apsubmit2015.html 14. https://apod.nasa.gov/apod/lib/aptree.html 15. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 16. https://apod.nasa.gov/apod/calendar/allyears.html 17. https://apod.nasa.gov/apod.rss 18. https://apod.nasa.gov/apod/lib/edlinks.html 19. https://apod.nasa.gov/apod/lib/about_apod.html 20. http://asterisk.apod.com/discuss_apod.php?date=230223 21. https://apod.nasa.gov/apod/ap230224.html 22. http://www.phy.mtu.edu/faculty/Nemiroff.html 23. http://www.phy.mtu.edu/ 24. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 25. http://www.astro.umd.edu/ 26. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 27. https://www.nasa.gov/about/highlights/HP_Privacy.html 28. https://astrophysics.gsfc.nasa.gov/ 29. https://www.nasa.gov/ 30. https://www.nasa.gov/centers/goddard/ 31. https://science.nasa.gov/learners 32. http://www.mtu.edu/