﻿ 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 April 11 [2]A bright star is seen in field of dimmer stars and pervasive light-brown dust. The star is the North Star: Polaris. Please see the explanation for more detailed information. North Star: Polaris and Surrounding Dust Image Credit & Copyright: [3]Javier Zayaz Explanation: Why is Polaris called the North Star? First, [4]Polaris is the nearest [5]bright star toward the north [6]spin axis of the Earth. Therefore, as the [7]Earth turns, stars appear to revolve around [8]Polaris, but Polaris itself always stays in the same northerly direction -- making it the [9]North Star. Since no bright star is near the [10]south spin axis of the Earth, there is currently [11]no bright South Star. Thousands of years ago, Earth's spin axis pointed in a slightly different direction so that [12]Vega was the North Star. Although [13]Polaris is [14]not the brightest star on the sky, it is easily located because it is [15]nearly aligned with two stars in the cup of the [16]Big Dipper. [17]Polaris is near the center of the eight-degree wide [18]featured image, a digital composite of hundreds of exposures that brings out faint gas and dust of the [19]Integrated Flux Nebula (IFN) all over the frame as well as the [20]globular star cluster [21]NGC 188 on the far left. The surface of [22]Cepheid Polaris slowly [23]pulsates, causing the famous star to [24]change its brightness by a few percent over the course of a few days. Explore Your Universe: [25]Random APOD Generator Tomorrow's picture: open space __________________________________________________________________ [26]< | [27]Archive | [28]Submissions | [29]Index | [30]Search | [31]Calendar | [32]RSS | [33]Education | [34]About APOD | [35]Discuss | [36]> __________________________________________________________________ Authors & editors: [37]Robert Nemiroff ([38]MTU) & [39]Jerry Bonnell ([40]UMCP) NASA Official: Phillip Newman [41]Specific rights apply. [42]NASA Web Privacy Policy and Important Notices A service of: [43]ASD at [44]NASA / [45]GSFC, [46]NASA Science Activation & [47]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2304/PolarisIfn_Zayaz_4000.jpg 3. https://www.instagram.com/javi_zayaz/ 4. https://en.wikipedia.org/wiki/Polaris 5. https://apod.nasa.gov/apod/ap221218.html 6. https://en.wikipedia.org/wiki/Axial_tilt#/media/File:AxialTiltObliquity.png 7. https://solarsystem.nasa.gov/planets/earth/in-depth/ 8. https://youtu.be/cDhSSxmk3PQ 9. https://earthsky.org/brightest-stars/polaris-the-present-day-north-star 10. https://apod.nasa.gov/apod/ap210101.html 11. https://astronomy.stackexchange.com/questions/6284/is-there-a-south-star 12. https://www.space.com/21719-vega.html 13. https://apod.nasa.gov/apod/ap150602.html 14. https://meowconnectioncom.files.wordpress.com/2017/02/296622-bigthumbnail.jpg 15. https://apod.nasa.gov/apod/ap201116.html 16. https://earthsky.org/favorite-star-patterns/big-and-little-dippers-highlight-northern-sky 17. https://upload.wikimedia.org/wikipedia/commons/c/cb/Ursa_Minor_IAU.svg 18. https://www.instagram.com/p/Cqa7IkRgYEj/ 19. https://apod.nasa.gov/apod/ap170627.html 20. https://en.wikipedia.org/wiki/Globular_cluster 21. https://en.wikipedia.org/wiki/NGC_188 22. https://starchild.gsfc.nasa.gov/docs/StarChild/questions/cepheids.html 23. https://youtu.be/7ohkKiZTJOg 24. https://youtu.be/q-szkabhXQQ 25. https://apod.nasa.gov/apod/random_apod.html 26. https://apod.nasa.gov/apod/ap230410.html 27. https://apod.nasa.gov/apod/archivepix.html 28. https://apod.nasa.gov/apod/lib/apsubmit2015.html 29. https://apod.nasa.gov/apod/lib/aptree.html 30. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 31. https://apod.nasa.gov/apod/calendar/allyears.html 32. https://apod.nasa.gov/apod.rss 33. https://apod.nasa.gov/apod/lib/edlinks.html 34. https://apod.nasa.gov/apod/lib/about_apod.html 35. https://asterisk.apod.com/discuss_apod.php?date=230411 36. https://apod.nasa.gov/apod/ap230412.html 37. http://www.phy.mtu.edu/faculty/Nemiroff.html 38. http://www.phy.mtu.edu/ 39. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 40. http://www.astro.umd.edu/ 41. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 42. https://www.nasa.gov/about/highlights/HP_Privacy.html 43. https://astrophysics.gsfc.nasa.gov/ 44. https://www.nasa.gov/ 45. https://www.nasa.gov/centers/goddard/ 46. https://science.nasa.gov/learners 47. http://www.mtu.edu/