The young ( \sim 16 Myr ) pre-main-sequence star in Sco–Cen 1SWASP J140747.93-394542.6 , hereafter referred to as J1407 , underwent a deep eclipse in 2007 April , bracketed by several shallower eclipses in the surrounding 54 d. This has been interpreted as the first detection of an eclipsing ring system circling a substellar object ( dubbed J1407b ) .
We report on a search for this companion with Sparse Aperture Mask imaging and direct imaging with both the UT4 VLT and Keck telescopes .
Radial velocity measurements of J1407 provide additional constraints on J1407b and on short period companions to the central star .
Follow-up photometric monitoring using the PROMPT-4 and ROAD observatories during 2012-2014 has not yielded any additional eclipses .
Large regions of mass-period space are ruled out for the companion .
For circular orbits the companion period is constrained to the range 3.5-13.8 yr ( a \simeq 2.2-5.6 au ) , and stellar masses ( > 80 M _ { Jup } ) are ruled out at 3 \sigma significance over these periods .
The complex ring system appears to occupy more than 0.15 of its Hill radius , much larger than its Roche radius and suggesting a ring structure in transition .
Further , we demonstrate that the radial velocity of J1407 is consistent with membership in the Upper Cen–Lup subgroup of the Sco–Cen association , and constraints on the rotation period and projected rotational velocity of J1407 are consistent with a stellar inclination of i _ { \star } \simeq 68 ^ { \circ } \pm 10 ^ { \circ } .