An Imaging Search for Post-Main-Sequence Planets of Sirius B

Abstract

We present deep imaging of Sirius B, the closest and brightest white dwarf, to constrain post-main-sequence planetary evolution in the Sirius system. We use Keck/NIRC2 in L'-band (3.776 $\mu$m) across three epochs in 2020 using the technique of angular differential imaging. Our observations are speckle-limited out to 1 AU and background-limited beyond. The 5$\sigma$ detection limits from our best performing epoch are 17 to 20.4 L' absolute magnitude. We consider multiple planetary formation pathways in the context of Sirius B's evolution to derive mass sensitivity limits, and achieve sub-Jupiter sensitivities at sub-AU separations, reaching 1.6 ${\mathrm{M}}_{\mathrm{J}}$ to 2.4 ${\mathrm{M}}_{\mathrm{J}}$ at 0.5 AU down to a sensitivity of 0.7 ${\mathrm{M}}_{\mathrm{J}}$ to 1.2 ${\mathrm{M}}_{\mathrm{J}}$ at >1 AU. Consistent with previous results, we do not detect any companions around Sirius B. Our strong detection limits demonstrate the potential of using high-contrast imaging to characterize nearby white dwarfs.

16 pages, 13 figures, accepted by the Astronomical Journal, code and extra figures available at https://github.com/mileslucas/sirius-b

References in corpus (19)

• Array Programming with NumPy
• scikit-image: Image processing in Python
• The Gaia mission
• On the Luminosity of Young Jupiters
• The frequency of planetary debris around young white dwarfs
• Fundamental limitations of high contrast imaging set by small sample statistics
• Foretellings of Ragnarök: World-engulfing Asymptotic Giants and the Inheritance of White Dwarfs
• Keplerian discs around post-AGB stars: a common phenomenon?
• Externally-polluted white dwarfs with dust disks
• A Giant Planet Candidate Transiting a White Dwarf
• orbitize!: A Comprehensive Orbit-fitting Software Package for the High-contrast Imaging Community
• The triple evolution dynamical instability: Stellar collisions in the field and the formation of exotic binaries
• Orbital eccentricities of binary systems with a former AGB star
• A Jovian analogue orbiting a white dwarf star
• The W. M. Keck Observatory infrared vortex coronagraph and a first image of HIP79124 B
• On-sky performance of the QACITS pointing control technique with the Keck/NIRC2 vortex coronagraph
• An Extreme-AO Search for Giant Planets around a White Dwarf --VLT/SPHERE performance on a faint target GD 50
• On the rotational velocity of Sirius A
• ADONIS high contrast infrared imaging of Sirius-B

Cited by in corpus (1)

• A New Method for Finding Nearby White Dwarf Exoplanets and Detecting Biosignatures