๐Ÿš€ ๅฎ‡ๅฎ™ใฎ่จ˜ๆ†ถใƒปใ‚ซใƒฌใƒณใƒ€ใƒผๆคœ็ดข
ใใ‚‡ใ† ใƒฉใƒณใƒ€ใƒ 
ใƒŽใƒดใ‚กใฎๅคœๆ˜Žใ‘ Dawn Before Nova
โš ๏ธ ็‰นๅฎšใฎๅ†™็œŸๅฎถใซใ‚ˆใ‚‹่‘—ไฝœ็‰ฉ
ใ“ใฎๅคœๆ˜Žใ‘ใซใพใŸๆ–ฐๆ˜Ÿ็ˆ†็™บใŒ่ตทใ“ใ‚‹ใฎใ ใ‚ใ†ใ‹๏ผŸ ๆฟ€ๅค‰ใ™ใ‚‹้€ฃๆ˜Ÿ็ณปใ‚’ๅ‘จๅ›žใ™ใ‚‹ๆƒ‘ๆ˜Ÿใซไฝใ‚€ๆœชๆฅใฎไบบ้กžใฏใ€ใ„ใคใ‹ใ“ใฎใ‚ˆใ†ใชใ‚ธใƒฌใƒณใƒžใซๆ€ใ„ใ‚’้ฆณใ›ใ‚‹ใ‹ใ‚‚ใ—ใ‚Œใชใ„ใ€‚ๆฟ€ๅค‰ใ™ใ‚‹้€ฃๆ˜Ÿ็ณปใจใฏใ€ๅทจๅคงใ ใŒใ‚ณใƒณใƒ‘ใ‚ฏใƒˆใช็™ฝ่‰ฒ็Ÿฎๆ˜Ÿใ‚’ๅ–ใ‚Šๅ›ฒใ‚€้™็€ๅ††็›คใซใ€ๅคงใใชๆ’ๆ˜Ÿใ‹ใ‚‰ใ‚ฌใ‚นใŒ่ฝไธ‹ใ™ใ‚‹็พ่ฑกใงใ‚ใ‚‹ใ€‚้™็€ๅ††็›คๅ†…้ƒจใฎใ‚ฌใ‚นๅกŠใŒไธ€ๅฎšใฎๆธฉๅบฆใ‚’่ถ…ใˆใฆๅŠ ็†ฑใ•ใ‚Œใ‚‹ใจใ€็Ÿฎๆ–ฐๆ˜Ÿใฎใ‚ˆใ†ใช็ˆ†็™บ็š„ใชๆฟ€ๅค‰็พ่ฑกใŒ็™บ็”Ÿใ™ใ‚‹ใ€‚ใใฎๆ™‚็‚นใงใ€ใ‚ฌใ‚นๅกŠใฏ็™ฝ่‰ฒ็Ÿฎๆ˜Ÿใซๆ€ฅ้€Ÿใซ่ฝไธ‹ใ—ใ€ๆ˜Žใ‚‹ใ„้–ƒๅ…‰ใ‚’ไผดใฃใฆ็€ๅœฐใ™ใ‚‹ใ€‚ใ“ใฎใ‚ˆใ†ใช็Ÿฎๆ–ฐๆ˜Ÿใฏใฉใกใ‚‰ใฎๆ’ๆ˜Ÿใ‚‚็ ดๅฃŠใ™ใ‚‹ใ“ใจใฏใชใใ€ๆ•ฐๆ—ฅใ‹ใ‚‰ๆ•ฐๅๅนดใฎๅ‘จๆœŸใงไธ่ฆๅ‰‡ใซ็™บ็”Ÿใ™ใ‚‹ๅฏ่ƒฝๆ€งใŒใ‚ใ‚‹ใ€‚ๆ–ฐๆ˜Ÿใฏ่ถ…ๆ–ฐๆ˜Ÿใ‚ˆใ‚Šใฏใ‚‹ใ‹ใซใ‚จใƒใƒซใ‚ฎใƒผใŒไฝŽใ„ใŒใ€็นฐใ‚Š่ฟ”ใ•ใ‚Œใ‚‹ๆ–ฐๆ˜ŸใŒใ€่ฝไธ‹ใ™ใ‚‹ใ‚ฌใ‚นใ‚ˆใ‚Šใ‚‚ๅคšใใฎใ‚ฌใ‚นใ‚’ๆ”พๅ‡บใ™ใ‚‹ใปใฉๆฟ€ใ—ใใชใ„ๅ ดๅˆใ€็™ฝ่‰ฒ็Ÿฎๆ˜Ÿใซ่ณช้‡ใŒ่“„็ฉใ•ใ‚Œใ€ใƒใƒฃใƒณใƒ‰ใƒฉใ‚ปใ‚ซใƒผใƒซ้™็•Œใ‚’่ถ…ใˆใ‚‹ใ“ใจใซใชใ‚‹ใ€‚ใใฎๆ™‚็‚นใงใฏใ€ๆ‰‹ๅ‰ใฎๆดž็ชŸใฏใปใจใ‚“ใฉไฟ่ญทใซใชใ‚‰ใชใ„ใ ใ‚ใ†ใ€‚ใชใœใชใ‚‰ใ€็™ฝ่‰ฒ็Ÿฎๆ˜Ÿๅ…จไฝ“ใŒๅทจๅคงใช่ถ…ๆ–ฐๆ˜Ÿ็ˆ†็™บใ‚’่ตทใ“ใ—ใฆใ—ใพใ†ใ‹ใ‚‰ใ ใ€‚
ๅŽŸๆ–‡๏ผˆEnglish๏ผ‰
Will this dawn bring another nova? Such dilemmas might be pondered one day by future humans living on a planet orbiting a cataclysmic variable binary star system. Cataclysmic variables involve gas falling from a large star onto an accretion disk surrounding a massive but compact white dwarf star. Explosive cataclysmic events such as a dwarf nova can occur when a clump of gas in the interior of the accretion disk heats up past a certain temperature. At that point, the clump will fall more quickly onto the white dwarf and land with a bright flash. Such dwarf novas will not destroy either star, and may occur irregularly on time scales from a few days to tens of years. Although a nova is much less energetic than a supernova, if recurrent novas are not violent enough to expel more gas than is falling in, mass will accumulate onto the white dwarf star until it passes its Chandrasekhar limit. At that point, a foreground cave may provide little protection, as the entire white dwarf star will explode in a tremendous supernova.

๏ผผ ใ“ใฎๆ„Ÿๅ‹•ใ‚’ๅฎ‡ๅฎ™ไปฒ้–“ใซใ‚ทใ‚งใ‚ข ๏ผ

ๅฎ‡ๅฎ™ใ‚’Xใงใ‚ทใ‚งใ‚ข
ยฉ Mark A. Garlick (Space-art.co.uk) / APOD