Friday, October 9, 2015

2M0441+2301 AabBab: a VERY Complicated System

Near-Infrared Spectroscopy of 2M0441+2301 AabBab: A Quadruple System Spanning the Stellar to Planetary Mass Regimes


Bowler et al


We present Keck/NIRC2 and OSIRIS near-infrared imaging and spectroscopy of 2M0441+2301 AabBab, a young (1--3 Myr) hierarchical quadruple system comprising a low-mass star, two brown dwarfs, and a planetary-mass companion in Taurus. All four components show spectroscopic signs of low surface gravity, and both 2M0441+2301 Aa and Ab possess Paβ emission indicating they each harbor accretion subdisks. Astrometry spanning 2008--2014 reveals orbital motion in both the Aab (0.23" separation) and Bab (0.095" separation) pairs, although the implied orbital periods of >300 years means dynamical masses will not be possible in the near future. The faintest component (2M0441+2301 Bb) has an angular H-band shape, strong molecular absorption (VO, CO, H2O, and FeH), and shallow alkali lines, confirming its young age, late spectral type (L1 ± 1), and low temperature (≈1800~K). With individual masses of 200+100−50 Mjup, 35 ± 5 Mjup, 19 ± 3 Mjup, and 9.8 ± 1.8 Mjup, 2M0441+2301 AabBab is the lowest-mass quadruple system known. Its hierarchical orbital architecture and mass ratios imply that it formed from the collapse and fragmentation of a molecular cloud core, demonstrating that planetary-mass companions can originate from a stellar-like pathway analogous to higher-mass quadruple star systems. More generally, cloud fragmentation may be an important formation pathway for the massive exoplanets that are now regularly being imaged on wide orbits.

1 comment:

  1. Hey, Cool blog! There's another very similar to yours in Beyond Earthly Skies, but he doesn't allow comments.

    Any idea how far this system is from earth? Secondly, if you were orbiting any of these planets (perhaps on a moon, as gas giants seem incapable of not having moons), how well could they see each other?

    This is Such an incredibly young system that if it is ever possible to go there, we really should, just to investigate the extreme proximity to the origins of geochemistry on said moons, which would make for quite a benchmark for verifying the 4th component of the Drake Equation.


Note: Only a member of this blog may post a comment.