The Circumstellar Disk at HD 15074

The Age of the HD 15407 System and the Epoch of Final Catastrophic Mass Accretion onto Terrestrial Planets around Sun-like Stars

http://arxiv.org/abs/1005.2451

Abstract wrote:

From optical spectroscopic measurements we determine that the HD 15407 binary system is ~80 Myr old. The primary, HD 15407A (spectral type F5V), exhibits strong mid-infrared excess emission indicative of a recent catastrophic collision between rocky planetary embryos or planets in its inner planetary system. Synthesis of all known stars with large quantities of dust in their terrestrial planet zone indicates that for stars of roughly Solar mass this warm dust phenomenon occurs at ages between 30 and 100 Myr. In contrast, for stars of a few Solar masses, the dominant era of the final assembling of rocky planets occurs earlier, between 10 and 30 Myr age. The incidence of the warm dust phenomenon, when compared against models for the formation of rocky terrestrial-like bodies, implies that rocky planet formation in the terrestrial planet zone around Sun-like stars is common.

The Absence of Cold Dust around Warm Debris Disk Star HD 15407A

No cold dust present which suggests it is not a Late Heavy Bombardment scenario. Furthermore there is so far no sign of SiO gas which might be expected in the aftermath of a giant impact, further investigation needed...

(incidentally the thread title needs a change...)