Keck Observations in the INfrared of Taurus and $\rho$ Oph Exoplanets And Ultracool dwarfs (KOINTREAU) II: Two Young Bound Companions to Ophiuchus Stars

Abstract

We present the second set of discoveries from Keck Observations in the INfrared of Taurus and $\rho$ Oph Exoplanets And Ultracool dwarfs (KOINTREAU), an adaptive optics survey of young stars in the Taurus and $\rho$ Oph star-forming regions using Keck/NIRC2 in conjunction with the Keck infrared pyramid wavefront sensor. We have discovered two faint comoving companions to young stars ISO-Oph 96 and 2MASS J16262785-2625152. The companion to ISO-Oph 96, KOINTREAU-3b, is at a projected separation of 340 au (2.49"). Using our NIRC2 photometry and evolutionary models, and assuming that the companion has the same extinction as its host star, we infer that KOINTREAU-3b has a mass of $3.4\pm 0.7$ M${}_{\mathrm{Jup}}$. The companion to 2MASS J16262785-2625152, KOINTREAU-4b, has a projected separation of 180 au (1.25") and could have a mass of either $11.5_{-1.6}^{+1.2}$ M${}_{\mathrm{Jup}}$ or $15.3_{-0.8}^{+0.7}$ M${}_{\mathrm{Jup}}$, depending on whether the host star is a member of $\rho$ Oph or Upper Sco.

References in corpus (37)

• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Gaia Data Release 3: Summary of the content and survey properties
• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Two accreting protoplanets around the young star PDS 70
• Accretion in the Rho-Oph pre-main sequence stars
• A Circumplanetary Disk Around PDS70c
• Direct Imaging and Spectroscopy of a Planetary Mass Candidate Companion to a Young Solar Analog
• The SPHERE infrared survey for exoplanets (SHINE). III. The demographics of young giant exoplanets below 300 au with SPHERE
• Planets Around Low-Mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems
• A VLT/NACO Survey for Triple and Quadruple Systems among Visual Pre-Main Sequence Binaries
• The Wide Brown Dwarf Binary Oph 1622-2405 and Discovery of A Wide, Low Mass Binary in Ophiuchus (Oph 1623-2402): A New Class of Young Evaporating Wide Binaries?
• Discovery of a wide planetary-mass companion to the young M3 star GU Psc
• The International Deep Planet Survey II: The frequency of directly imaged giant exoplanets with stellar mass
• Multiple protostellar systems. II. A high resolution near-infrared imaging survey in nearby star-forming regions
• Refining the Census of the Upper Scorpius Association with Gaia
• Stars with Photometrically Young Gaia Luminosities Around the Solar System (SPYGLASS) I: Mapping Young Stellar Structures and their Star Formation Histories
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds: VII. Ophiuchus Observed with MIPS
• AF Lep b: the lowest mass planet detected coupling astrometric and direct imaging data
• Direct imaging discovery of a super-Jovian around the young Sun-like star AF Leporis
• Astrometric Accelerations as Dynamical Beacons: A Giant Planet Imaged Inside the Debris Disk of the Young Star AF Lep
• X-Shooter study of accretion in $\rho$-Ophiucus: very low-mass stars and brown dwarfs
• The star formation history of Upper Scorpius and Ophiuchus
• The Gaia-ESO Survey: Membership probabilities for stars in 63 open and 7 globular clusters from 3D kinematics
• Deep near-IR variability survey of pre-main-sequence stars in Rho Ophiuchi
• The Gaia-ESO Survey: homogenisation of stellar parameters and elemental abundances
• A Survey for New Stars and Brown Dwarfs in the Ophiuchus Star-forming Complex
• The Second Discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) Program: A Cold Wide-Orbit Exoplanet around a Young Field M Dwarf at 10.9 pc
• The Gaia-ESO Survey: Calibrating the lithium-age relation with open clusters and associations. I. Cluster age range and initial membership selections
• The $\rho$ Oph region revisited with Gaia EDR3
• A Novel Survey for Young Substellar Objects with the W-band Filter. I. Filter Design and New Discoveries in Ophiuchus and Perseus
• A wide planetary-mass companion to a young low-mass brown dwarf in Ophiuchus
• A Significant Population of Candidate New Members of the Rho Ophiuchi Cluster
• USco1621 B and USco1556 B: Two wide companions at the deuterium-burning mass limit in Upper Scorpius
• Keck Observations in the INfrared of Taurus and $\rho$ Oph Exoplanets And Ultracool dwarfs (KOINTREAU) I: A Planetary-Mass Companion and a Disk-Obscured Stellar Companion Discovered in Taurus