1. astronomers: planet orbit stars, imagine system alike
-Yet: 15 years, differ
example1) 51 P: massive than J orbit smaller than M
(2)stranger: HD 40307
(3)55 Cancri A
2. white dwarf system: stars don't need to be unlike
-planet+planetary building orbit<=planet themselves
-variety equal( them & ordinary)
-astronomers don't expect ubiquity systems, hardiness, process of formation
-ours solar system not most common
3.1st extrasolar planet unsunlikeSR 1257
-mass greater than sun. 20km
-create: supernova explosion
-radius>1AU,
-both reasons: planets rose out of ashes of explosion
4.supernova eject most debris into interstellar space, small amount form disk around stellar remnant
-our solar system kept to form sun
5. discover system around PSR 1257 by deviations in timing of radio pulses
-deviations arise: orbiting planets pull slightly on the star
-though intensive search, no other comparable system
-another pulsar at least 1, so far-> didn't form fall back disk but was captured from another star
1. astronomers: planet orbit stars, imagine system alike
-Yet: 15 years, differ
example (1) 51 P: massive than J orbit smaller than M
(2)stranger: HD 40307
(3)55 Cancri A
2. white dwarf system: stars don't need to be unlike
-planet+planetary building orbit<=planet themselves
-variety equal( them & ordinary)
-astronomers don't expect ubiquity systems, hardiness, process of formation
-ours solar system not most common
3.1st extrasolar planet unsunlike SR 1257
-mass greater than sun. 20km
-create: supernova explosion
-radius>1AU,
-both reasons: planets rose out of ashes of explosion
4.supernova eject most debris into interstellar space, small amount form disk around stellar remnant
-our solar system kept to form sun
5. discover system around PSR 1257 by deviations in timing of radio pulses
-deviations arise: orbiting planets pull slightly on the star
-though intensive search, no other comparable system
-another pulsar at least 1, so far-> didn't form fall back disk but was captured from another star
1. Suspicion: there exists systems similar to solar system. Since 15 years ago, the findings have showed massive differences from solar system. Taking three examples to prove the point above.
2. In fact, variety is common thing in the universe. Solar systems might not be the most common in the universe
3. a very special neutron star PSR 1257+12, which survives in the massive explosion of a star 20 times the mass of the sun.
4. During the explosion of supernova, most of their debris had been ejected into interstellar space, a small amount of remnants would form as disk, which is the ground of planet. Some cloud and dust would settled into a pancake shape rather than falling to the newborn sun.
Astronomers keep tracking the periodic radio pulses due to periodically shifting