Агаар мандлын саад бэрхшээлээс ангид ажилласан агаарын бөмбөлөгт телескоп Нарны “чимээгүй” бүс дэх соронзон утаслаг бүтцийг илрүүллээ.
2024 онд хөөргөсөн SUNRISE III төслийн хүрээнд 35 км-ийн өндөрт, агаар мандлын ихэнх хэсгээс дээгүүр 1 метрийн диаметртэй нарны телескопыг байрлуулан ажиглалт хийжээ. Дэлхийн агаар мандлын үймээнээс зайлсхийснээр Нарны гадаргуу дээрх хамгийн жижиг соронзон онцлогуудыг өндөр нарийвчлалтайгаар дүрслэх боломж бүрдсэн байна. Судалгааны үр дүнг Astrophysical Journal Letters сэтгүүлд гурван тусдаа өгүүллээр нийтэлжээ.
Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) төхөөрөмж нь Нарны хромосфер дахь соронзон орны чиглэл болон хүчийг хэмжсэн байна. Урьд нь эрдэмтэд тус бүсийг босоо соронзон урсгалын хоолойнуудаар бүрхэгдсэн гэж үздэг байсан бол шинэ өгөгдлөөр 725 км-ийн өргөнтэй, хоорондоо ээлжлэн байрлах соронзон утаслагууд илэрлээ. Эдгээр утаслагийн соронзон хүч 10-20 Гаусс хооронд хэлбэлзэж байгаа нь нарны толбоны орчимд ажиглагддаг бүтэцтэй төстэй байна.
Судлаачид соронзон утаслагуудын туйлшрал гэнэт эсрэгээр өөрчлөгдөх үзэгдлийг “эсрэг туйлшрал бүхий нэвтрэлт” (OPI) хэмээн нэрлэжээ. MURaM-ChE алгоритм ашиглан хийсэн симуляцийн үр дүнд эдгээр нь 2,000-7,000 км урттай мушгирсан соронзон урсгалын олс болох нь тогтоогдсон байна. Энэхүү процесс нь соронзон энерги ялгаруулж, хүрээлэн буй плазмыг халаах боломжтой гэж эрдэмтэд тайлбарлажээ.
Түүнчлэн, Нарны туйл орчмоос цацардаг плазман тийрэлтэт урсгалын соронзон хүчийг анх удаа хэмжлээ. Хромосферийн доод хэсэгт соронзон орны хүч 10-20 Гаусс байсан бол дээд хэсэгт 40 Гаусс хүртэл өсөж байгааг ажиглажээ. Энэхүү өөрчлөлт нь бага өндөрт ажиглагдах соронзон өргөст бүтэц нягт байдагтай холбоотой багажийн хэмжилтийн онцлог байж болзошгүй гэж үзэж байна. Ирээдүйн SOLAR-C зэрэг сансрын төслүүд эдгээр соронзон бүтэц нь Нарны титмийг хэрхэн бүрдүүлж буйг илүү тодорхой болгох хүлээлттэй байна.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A balloon-borne telescope that flew in 2024 has revealed unexpected magnetic structure in the Sun’s so-called “quiet” regions. Three papers published in the Astrophysical Journal Letters now lay out what the SUNRISE III mission found, from tangled magnetic threads to a first good estimate of the field strength in solar jets.
Balloons are usually associated with parties, but they turn out to be useful scientific platforms too. SUNRISE III hung a suite of instruments, including a 1 m solar telescope, from a gondola beneath a helium balloon cruising at roughly 35 km, well above most of the air that blurs our view of the Sun.
That matters because Earth’s atmosphere is turbulent, and the turbulence smears the finest solar details, such as the smallest magnetic features. Lifting instruments above most of it sharpens the picture considerably, and a balloon does so without the mechanical constraints of a true rocket launch. Scientists have had time since the flight to assemble their results into three papers.
A Chromosphere Full of Surprises
The mission’s key instrument was the Sunrise Chromospheric Infrared spectroPolarimeter, or SCIP. It measured the full Stokes polarimetry of the Sun, which lets astronomers reconstruct magnetic field directions and strengths across several atmospheric layers.
Some of those layers belong to the “Quiet Sun,” the parts that attract far less attention than sunspots, which cover only a fraction of the solar surface. The chromosphere there had long been pictured as dominated by a “canopy” of vertical magnetic flux tubes. SCIP’s data tell a different story: the canopy is full of unexpected magnetic threads, each about 725 km across, which is small by solar standards. Their strength swings between 10 and 20 Gauss, in an alternating pattern similar to structures typically seen around sunspot penumbrae.
Occasionally, the threads flip their polarity completely relative to the canopy around them, a phenomenon called an “opposite-polarity intrusion,” or OPI. According to the researchers, the canopy field is not simply an expanding structure originating from network regions, but has a complex three-dimensional configuration with numerous localized sub-structures. They also say it looks like an ideal place for small-scale magnetic reconnection that could release energy to heat the surrounding plasma.
Twisted Ropes Behind the Flips
So what causes OPIs? A companion paper tackled that question, though it leaned on simulation rather than observation alone. The team used a 3D radiative-magnetohydrodynamic algorithm called MURaM-ChE and fed SUNRISE III data into it as input.
The simulated structures matched the observed OPIs extremely well, and the answer became obvious: they are twisted magnetic flux ropes. These will sound familiar to anyone who follows solar coverage, since such ropes come up whenever the Sun’s outer layer or its storms are discussed.
They measure around 2,000 to 7,000 km in length, and their reconnection appears to set up solar flares, thanks to the enormous energy that process releases. Now it seems they have threaded into its relatively calm surface too, although their breaking and disconnecting doesn’t appear to happen as often there.
Weighing Up the Polar Jets
The third paper turned to plasma jets that shoot out from the Sun’s poles. They have been implicated in delivering energy to the corona, yet nobody had managed to measure their true magnetic strength. Watching them with SCIP allowed scientists to produce a fairly accurate estimate.
The field strength in the lower canopy comes out between 10 and 20 Gauss, actually lower than earlier estimates would have predicted. Higher above the solar limb, the apparent edge of the Sun, it jumps to around 40 Gauss.
That jump may be an instrumentation trick. Low down, the thicket of spicules is so dense that telescopes cannot see through it and can only calculate values for the outermost ones. Further up, the canopy thins out, so the instruments can measure the spicules more directly.
The three papers show how complex even the quiet face of the solar disk is. Future missions such as SOLAR-C are hoped to shed more light on how these fields and ropes tie together to create the corona.
Enjoyed this article? Subscribe to our free newsletter for engaging stories, exclusive content, and the latest news.
