Free Astronomy Magazine July-August 2026

C lose-up of the central parts of the Sombrero Galaxy imaged by DECam. [CTIO/NOIRLab/DOE/ NSF/AURA. Image Processing: T.A. Rec- tor (University of Alaska Anchorage/ NSF NOIRLab), D. de Martin & M. Zamani (NSF NOIRLab)] JULY-AUGUST 2026 it by hand to his per- sonal copy. Independ- ently, in 1784, the well-known astrono- mer William Herschel also stumbled upon this remarkable galaxy and designated it as H I.43. It wasn’t until French astronomer Camille Flammarion’s subsequent confirma- tion that these two in- dependent discoveries were the same object that Messier 104 offi- cially earned its place in the Messier Cata- logue in 1921. Thus, through the col- laborative efforts of these astronomers across different eras, the Sombrero Galaxy has become a celebrated addition to our knowl- edge of deep sky objects. Its alluring visual characteristics, coupled with its accessibility to amateur equip- ment, contribute to Messier 104’s popularity among stargazers. Ama- teur astronomers often enjoy ob- serving and photographing the Sombrero Galaxy, making it a prime target for citizen science projects and public outreach efforts. It is an excellent subject for sharing the wonders of the Universe with the public and fostering engagement with astronomy and science. ! which appears to stretch over three times the width of the Sombrero it- self. This may be the first time the halo has been captured with this level of detail and at this large a scale. DECam’s incredible sensitivity also captured a sweeping stellar stream extending from the south side of the galaxy. The halo and the stellar stream are populated with stars that have been torn from their home galaxies, hinting at a past galactic merger between the Som- brero and a smaller satellite galaxy. The story of Messier 104’s discovery is intertwined with the endeavors of several prominent astronomers. It was initially spotted by the French astronomer and comet hunter Pierre Méchain in 1781 when he was an as- sociate of the renowned comet hunter Charles Messier. At that time, Messier was compiling a list of non-cometary celestial objects, now famously known as the Messier Catalogue, to aid other astronomers in distinguishing these objects from passing comets. Interestingly, Messier 104 did not find its place in the original publica- tion of Messier’s list. However, it was later discovered that Messier added ASTRO PUBLISHING