Abstract
The detection of emission lines associated with accretion processes is a direct method for studying how and where gas giant planets form, how young planets interact with their natal ...protoplanetary disk, and how volatile delivery to their atmosphere takes place. H
α
(
λ
= 0.656
μ
m) is expected to be the strongest accretion line observable from the ground with adaptive optics systems, and is therefore the target of specific high-contrast imaging campaigns. We present MagAO-X and Hubble Space Telescope (HST) data obtained to search for H
α
emission from the previously detected protoplanet candidate orbiting AS209, identified through Atacama Large Millimeter/submillimeter Array observations. No signal was detected at the location of the candidate, and we provide limits on its accretion. Our data would have detected an H
α
emission with
F
H
α
> 2.5 ± 0.3 × 10
−16
erg s
−1
cm
−2
, a factor 6.5 lower than the HST flux measured for PDS70 b. The flux limit indicates that if the protoplanet is currently accreting it is likely that local extinction from circumstellar and circumplanetary material strongly attenuates its emission at optical wavelengths. In addition, the data reveal the first image of the jet north of the star as expected from previous detections of forbidden lines. Finally, this work demonstrates that current ground-based observations with extreme adaptive optics systems can be more sensitive than space-based observations, paving the way to the hunt for small planets in reflected light with extremely large telescopes.
ABSTRACT
We report the confirmation of HIP 67506 C, a new stellar companion to HIP 67506 A. We previously reported a candidate signal at 2λ/D (240 mas) in L′ in MagAO/Clio imaging using the binary ...differential imaging technique. Several additional indirect signals showed that the candidate signal merited follow-up: significant astrometric acceleration in Gaia DR3, Hipparcos–Gaia proper motion anomaly, and overluminosity compared to single main-sequence stars. We confirmed the companion, HIP 67506 C, at 0.1 arcsec with MagAO-X in 2022 April. We characterized HIP 67506 C MagAO-X photometry and astrometry, and estimated spectral-type K7-M2; we also re-evaluated HIP 67506 A in light of the close companion. Additionally, we show that a previously identified 9 arcsec companion, HIP 67506 B, is a much further distant unassociated background star. We also discuss the utility of indirect signposts in identifying small inner working angle candidate companions.
MagAO-X system is a new adaptive optics for the Magellan Clay 6.5m telescope. MagAO-X has been designed to provide extreme adaptive optics (ExAO) performance in the visible. VIS-X is an ...integral-field spectrograph specifically designed for MagAO-X, and it will cover the optical spectral range (450 - 900 nm) at high-spectral (R=15.000) and high-spatial resolution (7 mas spaxels) over a 0.525 arsecond field of view. VIS-X will be used to observe accreting protoplanets such as PDS70 b and c. End-to-end simulations show that the combination of MagAO-X with VIS-X is 100 times more sensitive to accreting protoplanets than any other instrument to date. VIS-X can resolve the planetary accretion lines, and therefore constrain the accretion process. The instrument is scheduled to have its first light in Fall 2021. We will show the lab measurements to characterize the spectrograph and its post-processing performance.
The detection of emission lines associated with accretion processes is a
direct method for studying how and where gas giant planets form, how young
planets interact with their natal protoplanetary ...disk and how volatile delivery
to their atmosphere takes place. H$\alpha$ ($\lambda=0.656\,\mu$m) is expected
to be the strongest accretion line observable from the ground with adaptive
optics systems, and is therefore the target of specific high-contrast imaging
campaigns. We present MagAO-X and HST data obtained to search for H$\alpha$
emission from the previously detected protoplanet candidate orbiting AS209,
identified through ALMA observations. No signal was detected at the location of
the candidate, and we provide limits on its accretion. Our data would have
detected an H$\alpha$ emission with $F_\mathrm{H\alpha}>2.5\pm0.3
\times10^{-16}$ erg s$^{-1}$ cm$^{-2}$, a factor 6.5 lower than the HST flux
measured for PDS70b (Zhou et al., 2021). The flux limit indicates that if the
protoplanet is currently accreting it is likely that local extinction from
circumstellar and circumplanetary material strongly attenuates its emission at
optical wavelengths. In addition, the data reveal the first image of the jet
north of the star as expected from previous detections of forbidden lines.
Finally, this work demonstrates that current ground-based observations with
extreme adaptive optics systems can be more sensitive than space-based
observations, paving the way to the hunt for small planets in reflected light
with extremely large telescopes.
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