Одон орон судлаачид V445 Puppis системээс цагт 20 сая миль хүртэлх хурдтайгаар шидэгдэх хийн бөмбөлгүүдийг илрүүлж, уг ховор үзэгдлийн мөн чанарыг тогтоов.
2000 оны сүүлээр эхэлсэн V445 Puppis-ийн дэлбэрэлтээс үүдэн үүссэн өтгөн тоосонцрын үүл хорин жилийн турш тухайн системийг нууж байсан юм. Тоосонцор сийрэгжсэний дараа Уорвикийн их сургуулийн судлаач Жон Миллс тэргүүтэй баг уг систем нь цагаан одой од болон гелийн одны хослол болохыг тогтоожээ. Ихэнх нова дэлбэрэлт устөрөгчөөр баялаг материалаас бүрддэг бол V445 Puppis нь устөрөгчгүй, бараг бүхэлдээ гелигээс тогтсон гэдгээрээ онцлог юм.
Судлаачид NASA-гийн TESS, Hubble сансрын дуран, Европын өмнөд одон орон судлалын төвийн Very Large Telescope болон Өмнөд Африкийн том дурангийн мэдээллийг нэгтгэн дүгнэжээ. Энэхүү ажиглалтаар хоёр од нь 3.7 хоногт нэг удаа тойрог замаар эргэдэг болох нь тодорхой болсон байна. Гэвч дэлбэрэлтийн дараа үүссэн, маш өндөр хурдтай хөдөлж буй хийн “бөмбөлгүүд”-ийн үүсэл нь одоогоор тайлагдашгүй нууц хэвээр байна.
Энэхүү судалгаа нь орчлон ертөнцийн хамгийн тод дэлбэрэлтүүдийн нэг болох Ia төрлийн супернова дэлбэрэлтийн үйл явцыг ойлгоход чухал ач холбогдолтой юм. Устөрөгчгүй орчинд явагдах ийм төрлийн дэлбэрэлтүүд нь галактик хоорондын зайг хэмжих “стандарт лаа” болдог тул уг олдвор нь оддын хувьслыг судлах ховор боломжийг олгож байна.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Astronomers have discovered unexplained clumps of gas traveling at speeds of up to 20 million miles per hour from the explosion of V445 Puppis, the only confirmed helium nova in the Milky Way.The discovery has revealed the nature of the rare binary system behind the explosion while exposing a new mystery surrounding these high-speed structures.
The findings come after more than two decades of observations, during which a thick cloud of dust created by the eruption concealed the stars at the center of the event. As the debris gradually cleared, researchers were able to identify the system as a white dwarf feeding on material from a rare helium star companion.
Most known novae occur when a white dwarf collects hydrogen-rich material from a nearby star, triggering a thermonuclear explosion. V445 Puppis is different because the material involved is rich in helium and almost completely lacks hydrogen, making it a rare example of a hydrogen-poor stellar eruption.
The Royal Astronomical Society reported that the research led by John Mills from the University of Warwick confirms for the first time the nature of the binary system responsible for the only known helium nova in the galaxy. The study was presented at the society’s National Astronomy Meeting in Birmingham.
Dust Reveals the Source of a Rare Stellar Explosion
The eruption of V445 Puppis began in late 2000, producing a large bipolar outflow of material that expanded into space. The explosion also created a dense disk of dust that blocked direct observations of the stars responsible for the event.
For more than 20 years, astronomers could track the expanding debris but could not determine the exact nature of the system hidden at its center. As the dust became thinner, the binary system finally became visible, allowing researchers to investigate the origin of the unusual explosion.
The study shows that the system contains a white dwarf collecting material from a helium star. This type of star has lost its outer hydrogen envelope, probably through previous interactions with its companion, leaving behind a rare helium-rich object.
Researchers combined data from multiple observatories to examine the system. The observations included infrared measurements from the European Southern Observatory’s Very Large Telescope, images from the Hubble Space Telescope, spectroscopy from the Southern African Large Telescope, and observations from NASA’s TESS mission. The results provide the first detailed confirmation of the stars involved in V445 Puppis.
“V445 Puppis has long stood out among novae for its complete lack of hydrogen. How could such an event be completely devoid of the most abundant element in the universe?”saidJohn Mills, a researcher and doctoral student at the University of Warwick.
Fast-moving Gas Bullets Add A New Mystery
Inside the expanding debris surrounding V445 Puppis, researchers identified unusual clumps of material moving at extraordinary speeds. These gas “bullets” are traveling at up to 20 million miles per hour and may contain oxygen-rich gas.
Their origin remains unknown. Similar structures have not been observed in other novae, making these objects a unique feature of the eruption.
“The origin of these ‘bullets’ is a mystery,” Mills said. “We suspect that these originated post-outburst, but ‘bullets’ of this kind have not been observed in any other nova.”
The gas clumps were detected at both ends of the bipolar outflow produced by the explosion. Their position suggests they were linked to the aftermath of the eruption, but researchers have not yet determined how they formed.
The discovery adds another unusual element to V445 Puppis, a system already distinguished by its lack of hydrogen. Mills noted that the absence of hydrogen has long made the object difficult to explain because hydrogen is the most abundant element in the universe.
A Rare Laboratory for Studying Stellar Explosions
The new observations also revealed that the binary system is active again, with material continuing to move from the helium star toward the white dwarf. Researchers found that the two stars orbit each other every 3.7 days, around twice as long as previously estimated.
Helium stars are extremely rare objects. The research team estimates that only a few thousand stripped helium stars exist among the hundreds of billions of stars in the Milky Way. This makes V445 Puppis an important system for studying how helium-rich material behaves around a white dwarf.
Mills explained that repeated helium-rich eruptions could represent one possible route toward producing type Ia supernovae, some of the brightest explosions in the universe. These events are used by astronomers as standard candles because their consistent brightness helps measure distances to galaxies.
“I look forward to seeing how this result may help us uncover what powers other similar hydrogen-poor astronomical explosions, such as the famous Type Ia supernovae,”he added.
While V445 Puppis does not yet resolve how these explosions form, it provides a rare view of a hydrogen-poor stellar system and the processes occurring around one of the galaxy’s most unusual novae.
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