| |
 |
| Paper: |
New Observational Constraints on the Mass-Loss History of SN 1987A |
| Volume: |
313, Asymmetrical Planetary Nebulae III |
| Page: |
547 |
| Authors: |
Sugerman, B.E.K.; Crotts, A.P.S. |
| Abstract: |
Light echoes are an extremely powerful tool for precision three-dimensional mapping of dust in circumstellar (CSE) and interstellar (ISE) environments. We present light echoes from 9 years of imaging of SN 1987A, which reveal the fossil record of the progenitor's mass-loss history. The CSE is a richly-structured bipolar nebula, with an outer, double-lobed "peanut" extending 28 ly along the poles and 11 ly near the equator, but pinched to 6 ly at the waist, while interior, a cylindrical hourglass, 1 ly in radius and 4 ly long, connects to the peanut by a thick equatorial disk. Echo fluxes suggest that between the hourglass and bipolar lobes: the gas density drops from 1–3 cm−3 to > 0.03 cm−3; the maximum dust-grain size increases from ~ 0.2μm to 2μm; and the silicate:carbonaceous dust ratio decreases. The nebulae have a total mass of ~1.7MSolar, suggesting a red-supergiant mass loss of 5 × 10−6 MSolar yr−1 . |
|
|
|
|
|
