published today in\u00a0The Astrophysical Journal<\/a>.\u00a0<\/p>\nEach galaxy is far from other galaxies and has stopped making stars, a combination that is extremely rare. The discovery provides compelling observational evidence of a long-held astronomical theory.<\/p>\n
\u201cDwarf galaxies exist both in isolation and as satellites around larger galaxies like our own Milky Way,\u201d said Julian Shapiro, the study\u2019s sole author, who conducted his research while still in high school. \u201cIn isolation, these galaxies are expected to be actively forming stars, as there are no larger galaxies to strip their star-forming gas, but the galaxies I discovered break this rule. My paper argues that they may be among the first resolved \u2018backsplash\u2019 galaxy candidates, or galaxies that once passed close to a large neighbor, whose pressure removed their gas, before being flung outward.\u201d<\/p>\n
Usually, small dwarf galaxies found in isolated, low-density regions of deep space still contain cold gas that allows them to produce stars. Conversely, dwarf galaxies that have stopped forming stars \u2014 or have become \u201cquenched\u201d \u2014 are usually found in dense environments or near larger host galaxies, where strong hydrodynamic and gravitational forces siphon off their gas.<\/p>\n
The three dwarf galaxies Shapiro discovered present a puzzle: they are both isolated and quenched. Astrophysicists have been attempting to explain what causes these two traits to coexist.\u00a0<\/p>\n
Shapiro believes the three dwarf galaxies once plunged through the gravitational well of a massive host galaxy \u2014 with Messier 101, known as the Pinwheel Galaxy, being the primary candidate \u2014 where environmental forces violently stripped away their star-forming gas before flinging them out into deep space. Alternatively, Shapiro Dwarf Galaxy II lies close enough to spiral galaxy NGC 5585 to possibly be a faint satellite rather than a backsplash galaxy.<\/p>\n
![\"A](\"https:\/\/www.newsbeep.com\/us-ca\/wp-content\/uploads\/2026\/10\/backsplash_galaxies-768x512.jpg\")
\nA composite image created by Julian Shapiro using images from the Sloan Digital Sky Survey, Hyper Suprime-Cam Legacy Archive \/ National Astronomical Observatory of Japan, and Canada-France-Hawaii Telescope \/ Coelum. Courtesy of Julian Shapiro<\/p>\n
The standard cosmological model, referred to as lambda-cold dark matter (\u039bCDM), predicts that backsplash galaxies should be common, but identifying examples in the local universe has proven elusive. Shapiro\u2019s findings show that the standard physics model likely holds true even in milder cosmic neighborhoods while offering individual candidates to be confirmed through follow-up observations. The paper also lends credence to the hypothesis that external forces must be responsible for stripping isolated, quenched galaxies of their star formation ability.<\/p>\n
Shapiro used simulations to determine where backsplash dwarf galaxies were most likely to exist near a Milky Way-like galaxy and where the telescope archives could detect them. His paper proposes new methods for predicting the frequency of these galaxies.<\/p>\n
\u201cBuilding the foundational knowledge necessary to detect the galaxies, develop modeling and analysis code, and analyze the results in comparison to our cosmological model was a challenge,\u201d said Shapiro. \u201cI was fortunate that many of the leading journals in the field are free to access, which helped me gain an understanding of the necessary techniques and background.\u201d<\/p>\n
Much of Shapiro\u2019s research was spent estimating distances to determine whether the dwarf galaxies were truly isolated. He hopes that follow-up measurements from high-resolution space telescopes will definitively map the exact positions of the dwarf galaxies and rule out alternative scenarios for their quenched conditions. Shapiro expects that the new Vera C. Rubin Observatory will reveal many potential backsplash galaxies like the ones he uncovered.<\/p>\n
It is rare for any undergraduate student to publish their own research, but Shapiro\u2019s case is especially notable as he originally conducted his research while in high school. Now in his first semester at Berkeley, Shapiro is taking astrophysics courses \u2014 along with some math and physics requirements \u2014 in pursuit of an eventual major.\u00a0<\/p>\n
\u201cI envision my work serving as inspiration for young people aspiring to pursue research in astrophysics,\u201d said Shapiro. \u201cOften, school curriculums provide limited introductions to astronomy, and it is difficult for students to find mentorship and build experience in the field. My paper demonstrates that public archival telescope data is a critical tool for new discoveries in our understanding of cosmology and how our universe evolved, and that young astronomers are capable of uncovering these findings.\u201d<\/p>\n
![\"Julian](\"https:\/\/www.newsbeep.com\/us-ca\/wp-content\/uploads\/2026\/10\/Photo-with-Mentor-Alex-Filippenko-Shannon-Kelli-768x601.jpg\")
\nJulian Shapiro (right) poses with Alex Filippenko, a mentor and Berkeley astronomy professor.<\/p>\n
The Davidson Institute recognized Shapiro\u2019s backsplash galaxy research by naming him\u00a0a 2026 Davidson Fellow<\/a>. He also won the Astronomical League\u2019s National Young Astronomer Award in 2025.<\/p>\nCelebrated Berkeley astronomy professor Alex Filippenko praised the advanced manner in which Shapiro conducted his research and analyzed his findings.<\/p>\n
\u201cJulian conducted some remarkably sophisticated research while still in high school, which is highly unusual and was recognized with the prestigious Davidson Fellowship,\u201d said Filippenko. \u201cI feel very fortunate that he chose UC Berkeley for his undergraduate studies in astrophysics, and especially that he decided to join my research team.\u201d<\/p>\n
Shapiro will work with Filippenko\u2019s research group to study the Hubble tension \u2014 a scientific disagreement over the universe\u2019s rate of expansion. He is also hoping to conduct follow-up observations of the Shapiro Dwarf Galaxies.<\/p>\n","protected":false},"excerpt":{"rendered":"A new study by a first-year student may solve a puzzle regarding isolated galaxies that have stopped producing…\n","protected":false},"author":2,"featured_media":487771,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[139452,143,145,144,139450,139451],"class_list":["post-487770","post","type-post","status-publish","format-standard","has-post-thumbnail","category-oakland","tag-faculty-excellence","tag-oakland","tag-oakland-headlines","tag-oakland-news","tag-research-berkeley","tag-uc-berkeley-research"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/487770","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/comments?post=487770"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/487770\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media\/487771"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media?parent=487770"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/categories?post=487770"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/tags?post=487770"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"Julian](\"https:\/\/www.newsbeep.com\/us-ca\/wp-content\/uploads\/2026\/10\/Portrait-with-Observatory-Shannon-Kelli-768x512.jpg\")