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. 2025 September 23 [2]Stars dot the frame that has a blue background. Covering the lower part of the image, and the far right, are brown and tan nebular structures. Please see the explanation for more detailed information. NGC 6357: Cathedral to Massive Stars Image Credit: [3]NASA, [4]ESA, [5]CSA, [6]STScI, [7]JWST; Processing: [8]Alyssa Pagan ([9]STScI); Rollover: [10]NASA, [11]ESA, [12]HST, & J. M. Apellániz ([13]IAA, Spain); Acknowledgement: D. De Martin ([14]ESA/Hubble) Explanation: How massive can a normal star be? Estimates made from distance, brightness and standard [15]solar models had given one star in the [16]open cluster Pismis 24 over [17]200 times the mass of our [18]Sun, making it one of the [19]most massive stars known. This [20]star is the brightest object [21]located in the central [22]cavity near the bottom center of the [23]featured image taken with the [24]Webb Space Telescope in [25]infrared light. For comparison, a [26]rollover image from the [27]Hubble Space Telescope is also featured in [28]visible light. Close inspection of the [29]images, however, has shown that Pismis 24-1 derives its brilliant luminosity [30]not from a single star but from [31]three at least. [32]Component stars would still remain near 100 solar masses, [33]making them among the more [34]massive stars currently on record. Toward the bottom of the image, [35]stars are still forming in the associated [36]emission nebula [37]NGC 6357. Appearing perhaps like a [38]Gothic cathedral, energetic stars near the center appear to be [39]breaking out and illuminating a [40]spectacular cocoon. Teachers & Students: [41]Ideas for Utilizing APOD in the Classroom Tomorrow's picture: black hole bang __________________________________________________________________ [42]< | [43]Archive | [44]Submissions | [45]Index | [46]Search | [47]Calendar | [48]RSS | [49]Education | [50]About APOD | [51]Discuss | [52]> __________________________________________________________________ Authors & editors: [53]Robert Nemiroff ([54]MTU) & [55]Jerry Bonnell ([56]UMCP) NASA Official: Amber Straughn [57]Specific rights apply. [58]NASA Web Privacy, [59]Accessibility, [60]Notices; A service of: [61]ASD at [62]NASA / [63]GSFC, [64]NASA Science Activation & [65]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2509/Ngc6357_Webb_6357.jpg 3. https://www.nasa.gov/ 4. https://www.esa.int/ 5. https://www.asc-csa.gc.ca/eng/ 6. https://www.stsci.edu/ 7. https://science.nasa.gov/mission/webb/ 8. https://www.friendsofnasa.org/2023/03/behind-mission-alyssa-pagan-james-webb.html 9. https://www.stsci.edu/ 10. https://www.nasa.gov/ 11. https://www.esa.int/ 12. https://science.nasa.gov/mission/hubble/ 13. https://www.iaa.es/ 14. https://www.spacetelescope.org/ 15. http://spiff.rit.edu/classes/phys230/lectures/star_age/star_age.html 16. https://apod.nasa.gov/apod/open_clusters.html 17. https://en.wikipedia.org/wiki/NGC_6357#Pismis_24 18. https://science.nasa.gov/sun/ 19. https://en.wikipedia.org/wiki/List_of_most_massive_stars 20. https://science.nasa.gov/universe/stars/ 21. https://www.youtube.com/watch?v=iLbY7PYzku8 22. https://t3.ftcdn.net/jpg/08/33/26/14/360_F_833261466_b88xwq428xBEi2IEabTgX9jXOGjozkXR.jpg 23. https://webbtelescope.org/contents/news-releases/2025/news-2025-136 24. https://science.nasa.gov/mission/webb/ 25. https://science.nasa.gov/ems/07_infraredwaves/ 26. https://www.htmldog.com/techniques/rollovers/ 27. https://science.nasa.gov/mission/hubble/ 28. https://science.nasa.gov/ems/09_visiblelight/ 29. https://esawebb.org/news/weic2518/ 30. https://www.spacetelescope.org/news/heic0619/ 31. https://ui.adsabs.harvard.edu/abs/2007ApJ...660.1480M/abstract 32. https://apod.nasa.gov/apod/ap160205.html 33. https://ui.adsabs.harvard.edu/abs/2021A&A...647A.154B/abstract 34. https://en.wikipedia.org/wiki/List_of_most_massive_stars 35. http://asterisk.apod.com/viewtopic.php?f=24&t=18010 36. https://apod.nasa.gov/apod/emission_nebulae.html 37. https://apod.nasa.gov/apod/ap081009.html 38. http://upload.wikimedia.org/wikipedia/commons/6/65/Catedral_Metropolitana_de_Sao_Paulo_1_Brasil-edit-01.jpg 39. http://cdn.images.express.co.uk/img/dynamic/1/590x/cat-439127.jpg 40. https://apod.nasa.gov/apod/ap231224.html 41. https://apod.nasa.gov/apod/lib/apodclass.html 42. https://apod.nasa.gov/apod/ap250922.html 43. https://apod.nasa.gov/apod/archivepix.html 44. https://apod.nasa.gov/apod/lib/apsubmit2015.html 45. https://apod.nasa.gov/apod/lib/aptree.html 46. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 47. https://apod.nasa.gov/apod/calendar/allyears.html 48. https://apod.com/feed.rss 49. https://apod.nasa.gov/apod/lib/edlinks.html 50. https://apod.nasa.gov/apod/lib/about_apod.html 51. https://asterisk.apod.com/discuss_apod.php?date=250923 52. https://apod.nasa.gov/apod/ap250924.html 53. http://www.phy.mtu.edu/faculty/Nemiroff.html 54. http://www.phy.mtu.edu/ 55. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 56. http://www.astro.umd.edu/ 57. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 58. https://www.nasa.gov/about/highlights/HP_Privacy.html 59. https://www.nasa.gov/general/accessibility/ 60. https://www.nasa.gov/privacy/ 61. https://astrophysics.gsfc.nasa.gov/ 62. https://www.nasa.gov/ 63. https://www.nasa.gov/centers/goddard/ 64. https://science.nasa.gov/learners 65. http://www.mtu.edu/