The Disk Around CoKu Tauri/4: Circumbinary, Not Transitional

By Michael J. Ireland, A. Kraus. 2008

173 citations recorded by the source corpus.

CoKu Tau/4 has been labeled as one of the very few known transition disk objects—disks around young stars that have their inner disks cleared of dust, arguably as a result of planetary formation. We report aperture-masking interferometry and adaptive optics imaging observations showing that CoKu Tau/4 is in fact a near-equal binary star of projected separation ~53 mas (~8 AU). The spectral energy distribution of the disk is then naturally explained by the inner truncation of the disk through gravitational interactions with the binary star system. We discuss the possibility that such “unseen” binary companions could cause other circumbinary disks to be labeled as transitional.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/4001da3c10b12de4707c22020584e86f45e3abf6

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In Astronomy and Astrophysics

1. S. Andrews
2. D. Wilner
3. Jonathan P. Williams
4. K. Luhman
5. A. Kraus
6. N. Calvet
7. C. Dullemond
8. L. Hartmann

Citations in the corpus

• Protoplanetary disk lifetimes vs stellar mass and possible implications for giant planet populations (2015, background): “They include transitional and hot debris disks, as well as a small fraction of edge-on disks (e.g. Huélamo et al. 2010) and circumbinary disks (e.g. Ireland & Kraus 2008).”
• CRYSTALLINE SILICATES AND DUST PROCESSING IN THE PROTOPLANETARY DISKS OF THE TAURUS YOUNG CLUSTER (2007, background): “The end structure, and spectrum, might resemble those of CoKu Tau/4, for which the outer disk is apparently not very massive, though in this case the disk appears to be truncated by the binary star it contains (Ireland & Kraus 2008) instead of a giant planet.”
• RESOLVED IMAGES OF LARGE CAVITIES IN PROTOPLANETARY TRANSITION DISKS (2011, background): “…to explain observations of transition disks, including extensive particle growth (Tanaka et al. 2005; Dullemond & Dominik 2005), photoevaporative massloss in winds (Clarke et al. 2001; Alexander et al. 2006a), and tidal interactions with companions (e.g., Rice et al. 2003a; Ireland & Kraus 2008).”
• Individual Dynamical Masses of Ultracool Dwarfs (2017, methodology): “Analysis of our NIRC2 masking data was performed using a pipeline similar to previous papers (e.g., Ireland et al. 2008; Ireland & Kraus 2008) and is described in detail in Section 2.2 of Dupuy et al. (2009c).”
• A SPITZER SURVEY OF MID-INFRARED MOLECULAR EMISSION FROM PROTOPLANETARY DISKS. I. DETECTION RATES (2010, background): “CoKu Tau/4 is not a true disk in transition since dust and gas appears to have been cleared out by a stellar companion and not as a result of disk evolution (Ireland & Kraus 2008).”
• LARGE-SCALE ASYMMETRIES IN THE TRANSITIONAL DISKS OF SAO 206462 AND SR 21 (2014, unknown): “…photo evaporation, grain growth, and planet formation shape the structure of circumstellar disks (Clarke et al. 2001; Dullemond & Dominik 2005; Ireland & Kraus 2008), and in particular, the process of planet formation creates gaps, cavities, and asymmetries that can be directly observed (Wolf…”
• Imaging Extrasolar Giant Planets (2016, background): “This approach has been quite fruitful, resulting in the discovery of companions within these gaps spanning the stellar (CoKu Tau 4: Ireland & Kraus 2008; HD 142527: Biller et al. 2012, Close et al. 2014, Rodigas et al. 2014, Lacour et al. 2015), brown dwarf (HD 169142: Biller et al. 2014, Reggiani…”
• Protoplanetary Disks and Their Evolution (2011, methodology): “UY Aur (Duvert et al. 1998) and CoKu Tau 4 (Ireland & Kraus 2008) are additional examples of primordial circumbinary disks but they appear to be rare exceptions rather than the rule.”
• Gaps and Rings in an ALMA Survey of Disks in the Taurus Star-forming Region (2018, background): “Some outliers may be expected from this relationship for circumbinary disks, such as the disk around CoKu Tau 4 (D’Alessio et al. 2005; Ireland & Kraus 2008).”
• GIANT PLANET MIGRATION, DISK EVOLUTION, AND THE ORIGIN OF TRANSITIONAL DISKS (2009, background): “…surveys using high-resoluti n imaging have discovered significant numbers of close binaries even in regions that had previously been well studied (Ireland & Kraus 2008; Kraus et al. 2008), suggesting that the fraction of stars that exist as binaries with separations of∼ 3–30AU is not well…”
• THE IMPACT OF STELLAR MULTIPLICITY ON PLANETARY SYSTEMS. I. THE RUINOUS INFLUENCE OF CLOSE BINARY COMPANIONS (2016, background): “Also, some close binary systems (such as CoKu Tau/4; Ireland & Kraus 2008) clearly still host disks and therefore might plausibly produce planets.”
• THE ROLE OF MULTIPLICITY IN DISK EVOLUTION AND PLANET FORMATION (2011, background): “As we showed for the case of CoKu Tau/4 (Ireland & Kraus 2008), the large inner gap caused by a short-period binary system could masquerade as a signpost for planet formation, indicating that binary vetting is required for the so-called “transitional disk” systems.”
• THE DISK POPULATION OF THE TAURUS STAR-FORMING REGION (2009, background): “Taurus members that are known to harbor transitional disks include CoKu Tau/4, GM Aur, and DM Tau (Rice et al. 2003; Forrest et al. 2004; Quillen et al. 2004; Calvet et al. 2005; D’Alessio et al. 2005), although the inner hole in the disk of CoKu Tau/4 was probably produced by a stellar companion ra”
• Spectroastrometric Imaging of Molecular Gas within Protoplanetary Disk Gaps (2008, background): “A stellar companion orbiting at &1AU, but too close to the primary to be resolved with direct imaging, would clear out a large hole completely (Artymowicz & Lubow 1994), such as is the case for CoKu Tau/4 (Ireland & Kraus 2008).”
• LkCa 15: A YOUNG EXOPLANET CAUGHT AT FORMATION? (2011, background): “The example of CoKu Tau/4 demonstrates that “transitional disks” can host binary companions (Ireland & Kraus 2008), and other binary systems, like HK Tau and HV Tau, are known to have wider components which are obscured in this way (Stapelfeldt et al. 1998, 2003).”
• TRANSITIONAL DISKS AS SIGNPOSTS OF YOUNG, MULTIPLANET SYSTEMS (2011, background): “The prosaic explanation for wide holes in transitional disks—tidal truncation of the disk by a stellar companion, as observed in CoKu Tau/4 (Ireland & Kraus 2008)—is also not likely responsible for the unusual and complex disks that concern us in this article.”
• A SPATIALLY RESOLVED INNER HOLE IN THE DISK AROUND GM AURIGAE (2009, result): “A notable example is the recent result by Ireland & Kraus (2008) demonstrating that the inner hole in the transition disk around CoKu Tau/4 is caused by a previously unobserved companion.”