๐Ÿš€ ๅฎ‡ๅฎ™ใฎ่จ˜ๆ†ถใƒปใ‚ซใƒฌใƒณใƒ€ใƒผๆคœ็ดข
ใใ‚‡ใ† ใƒฉใƒณใƒ€ใƒ 
ๅ…‰ๅญใŒๅ‘จๅ›žใ™ใ‚‹ๆ˜Ÿ A Star Where Photons Orbit
โš ๏ธ ็‰นๅฎšใฎๅ†™็œŸๅฎถใซใ‚ˆใ‚‹่‘—ไฝœ็‰ฉ
ไธŠ่จ˜ใฎใ‚ณใƒณใƒ”ใƒฅใƒผใ‚ฟใƒผใ‚ขใƒ‹ใƒกใƒผใ‚ทใƒงใƒณ็”ปๅƒใฏใ€้žๅธธใซใ‚ณใƒณใƒ‘ใ‚ฏใƒˆใชๆ’ๆ˜ŸใŒ่ฟ‘ใใฎ่ฆณๆธฌ่€…ใ‹ใ‚‰ใฉใฎใ‚ˆใ†ใซ่ฆ‹ใˆใ‚‹ใ‹ใ‚’็คบใ—ใฆใ„ใพใ™ใ€‚ใ“ใฎ็”ปๅƒใซๆใ‹ใ‚Œใฆใ„ใ‚‹ๆ’ๆ˜Ÿใฏใ€ใƒ–ใƒฉใƒƒใ‚ฏใƒ›ใƒผใƒซใ‚’้™คใ‘ใฐๆ—ข็Ÿฅใฎใฉใฎๆ’ๆ˜Ÿใ‚ˆใ‚Šโ€‹โ€‹ใ‚‚ใ‚ณใƒณใƒ‘ใ‚ฏใƒˆใงใ‚ใ‚‹ใŸใ‚ใ€ใ‚ใใพใงไปฎ่ชฌไธŠใฎใ‚‚ใฎใงใ™ใ€‚่ฆณๆธฌ่€…ใฏๅ…‰ๅญ็ƒใซไฝ็ฝฎใ—ใฆใŠใ‚Šใ€ใใ“ใงใฏๅ…‰ๅญใŒๅ††่ปŒ้“ใ‚’ๆใ„ใฆๅ‘จๅ›žใงใใพใ™ใ€‚้‡ๅŠ›ใซใ‚ˆใฃใฆ็”Ÿใ˜ใ‚‹ๅคงใใชๆญชใฟใ‚’ใ‚ˆใ‚Šๅˆ†ใ‹ใ‚Šใ‚„ใ™ใใ™ใ‚‹ใŸใ‚ใซใ€ๅœฐ็ƒใฎๅœฐๅ›ณใŒๆ’ๆ˜ŸใซๆŠ•ๅฝฑใ•ใ‚Œใ€่ฆ‹ๆ…ฃใ‚ŒใŸๅคœ็ฉบใฎๅœฐๅ›ณใŒไธŠๆ–นใซๆŠ•ๅฝฑใ•ใ‚Œใฆใ„ใพใ™ใ€‚ใ“ใ“ใ‹ใ‚‰ใ€ไธ‹ใ‚’่ฆ‹ใ‚Œใฐๆ’ๆ˜Ÿใฎ่กจ้ขๅ…จไฝ“ใฎ่ค‡ๆ•ฐใฎ่ค‡่ฃฝๅƒใŒ่ฆ‹ใˆใ€ไธŠใ‚’่ฆ‹ใ‚Œใฐๅคœ็ฉบๅ…จไฝ“ใฎ่ค‡ๆ•ฐใฎ่ค‡่ฃฝๅƒใŒ่ฆ‹ใˆใ€ๅ…‰ๅญ็ƒใซๆฒฟใฃใฆ่ฆ‹ใ‚Œใฐ่‡ชๅˆ†ใฎๅพŒ้ ญ้ƒจใŒ่ฆ‹ใˆใ‚‹ใ€ใจใ„ใ†ใ‚ˆใ†ใซใ€ๆง˜ใ€…ใช่ฆ–็‚นใ‹ใ‚‰่ฆ‹ใ‚‹ใ“ใจใŒใงใใพใ™ใ€‚
ๅŽŸๆ–‡๏ผˆEnglish๏ผ‰
The above computer animated picture depicts how a very compact star would look to a nearby observer. The star pictured is actually more compact that any known except a black hole, so it is only hypothetical. The observer is situated at the photon sphere, where photons can orbit in a circle. To help the viewer better visualize the great distortions created by gravity, a map of the Earth was projected onto the star, and a map of the familiar night sky was projected above. From here one can either look down and see several duplicate images of the entire surface of the star, look up and see several duplicate images of the entire night sky, or look along the photon sphere and see the back of one's own head.

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

ๅฎ‡ๅฎ™ใ‚’Xใงใ‚ทใ‚งใ‚ข
ยฉ Robert Nemiroff, (GMU, NASA/ GSFC) / APOD