Extreme asymmetry in the polarized disk of V1247 Orionis

Abstract

We present the first near-infrared scattered-light detection of the transitional disk around V1247 Ori, which was obtained using high-resolution polarimetric differential imaging observations with Subaru/HiCIAO. Our imaging in the H band reveals the disk morphology at separations of ∼ 0. ′′ 14-0. ′′ 86 (54-330 au) from the central star. The polarized intensity (P I) image shows a remarkable arc-like structure toward the southeast of the star, whereas the fainter northwest region does not exhibit any notable features. The shape of the arm is consistent with an arc of 0. ′′ 28 ± 0. ′′ 09 in radius (108 au from the star), although the possibility of a spiral arm with a small pitch angle cannot be excluded. V1247 Ori features an exceptionally large azimuthal contrast in scattered, polarized light; the radial peak of the southeastern arc is about three times brighter than the northwestern disk measured at the same distance from the star. Combined with the previous indication of an inhomogeneous density distribution in the gap at < ∼ 46 au, the notable asymmetry in the outer disk suggests the presence of unseen companions and/or planet-forming processes ongoing in the arc.3

External or internal companion exciting the spiral arms in CQ Tau?

“…Similarly, the binary system HD 34700 features a spiral of greater radial extent and pitch angle relative to a series of smaller spirals present in scattered light images (Monnier et al 2019). Our mass limits support an analogous scenario, although CQ Tau features a smaller dust cavity compared to HD 142527 (∼90 au) and lacks the extreme dust asymmetry of V1247 Ori, HD 142527 and HD 34700 (Ohta et al 2016;Pérez et al 2014;Benac et al 2020, respectively).…”

“…Figure 7 shows the S1 spiral arm connects into a large-scale velocity perturbation in the 12 CO data, suggesting that this is part of a broader spiral structure (Wölfer et al 2021). A single large-scale or far-reaching spiral is not unusual, as seen in polarised light images of HD 100546, V1247 Ori and HD 142527 (de Boer et al 2021;Ohta et al 2016;Avenhaus et al 2014, respectively). In the case of HD 142527, all disc features have been qualitatively reproduced by the simulated interaction of the disc and an inclined, eccentric binary companion (Price et al 2018).…”

Near-infrared Imaging of a Spiral in the CQ Tau Disk

“…The CQ Tau disk has a striking similarity with the disk around V1247 -both of which show one prominent arm in scattered light and a ringed disk in mm continuum emission (Ohta et al 2016;Kraus et al 2017). In addition, they share a similar inclination of ∼ 30 − 35 • , and the major spiral arm seen is in the direction of the major axis.…”

Taxonomy of protoplanetary discs observed with ALMA

“…11 compares the morphology seen in scattered light with the morphology seen in sub-mm for the 27 protoplanetary discs. The Spiral substructure seen in scattered light observations has previously been seen in a number of protoplanetary discs (Grady et al 2001(Grady et al , 2013Fukagawa et al 2004 ;Casassus et al 2012 ;Muto et al 2012 ;Wagner et al 2015 ;Akiyama et al 2016 ;Ohta et al 2016 ;Canovas et al 2018 ). The submillimetre counterpart observations to these discs, ho we ver, sho w large cavities and axisymmetric substructure (Isella et al 2013 ;van der Marel et al 2013 ;Ansdell et al 2016 ;Kraus et al 2017 ;Tang et al 2017 ;Cazzoletti et al 2018 ;Dong et al 2018 ;Ohashi et al 2018 ;Pineda et al 2019 ).…”