Near-Ir Photometric Study of the Fu Orionis Object HBC 722

Sung, Hwankyung; Park, Won Kee; Yang, Yuna; Lee, Sang Gak; Yoon, Tae Seog; Lee, Jeong Eun; Kang, Wonseok; Park, Keun Hong; Cho, Dong Hwan; Park, Sunkyung

doi:10.5303/jkas.2013.46.6.253

Cited by 9 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These bluer colors were measured and discussed previously (Semkov et al 2014;Baek et al 2015;Kóspál et al 2016) and interpreted as an increase in emission from higher temperature material. Meanwhile, the near-IR colors stays consistent to within ∼0.05 mag in J − H and 0.15 mag in J − K during the brightness changes, with no strong dependence on brightness (Miller et al 2011;Sung et al 2013;Kóspál et al 2016).…”

Section: Hbc 722: Infrared Colors As Diagnostics Of Extinctionmentioning

confidence: 68%

Diagnosing FU Ori-like Sources: The Parameter Space of Viscously Heated Disks in the Optical and Near-infrared

Liu

Herczeg

Johnstone

et al. 2022

ApJ

Self Cite

View full text Add to dashboard Cite

FU Ori-type objects (FUors) are decades-long outbursts of accretion onto young stars that are strong enough to viscously heat disks so that the disk outshines the central star. We construct models for FUor objects by calculating emission components from a steady-state viscous accretion disk, a passively-heated dusty disk, magnetospheric accretion columns, and the stellar photosphere. We explore the parameter space of the accretion rate M ̇ and stellar mass M * to investigate implications on the optical and near-infrared spectral energy distribution and spectral lines. The models are validated by fitting to multiwavelength photometry of three confirmed FUor objects, FU Ori, V883 Ori, and HBC 722, and then comparing the predicted spectra to the observed optical and infrared spectra. The brightness ratio between the viscous disk and the stellar photosphere, η, provides an important guide for identifying viscous accretion disks, with η = 1 (“transition line”) and η = 5 (“sufficient dominance line”) marking turning points in diagnostics, evaluated here in the near-infrared. These turning points indicate the emergence and complete development of FUor-characteristic strong CO absorption, weak metallic absorption, the triangular spectral continuum shape in the H band, and location in color–magnitude diagrams. Lower M * and higher M ̇ imply larger η; for M * = 0.3 M ⊙, η = 1 corresponds to M ̇ = 2 × 10 − 7 M ⊙ yr−1 and η = 5 to M ̇ = 6 × 10 − 7 M ⊙ yr−1. The “sufficient dominance line” also coincides with the expected accretion rate where accreting material directly reaches the star. We discuss implications of the models on extinction diagnostics, FUor brightening timescales, viscous disks during initial protostellar growth, and eruptive young stellar objects associated with FUors.

show abstract

Section: Hbc 722: Infrared Colors As Diagnostics Of Extinctionmentioning

confidence: 68%

Diagnosing FU Ori-like Sources: The Parameter Space of Viscously Heated Disks in the Optical and Near-infrared

Liu

Herczeg

Johnstone

et al. 2022

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…None of the sources showed significant mid-IR (WISE bands 1 and 2) variability in 2010-2011 (Cutri & et al 2012(Cutri & et al , 2013. Extrapolating their data from June 2013, the optical brightness of the source has not varied significantly, and thus we take the K s mag as unchanged from 2013 (Sung et al 2013, Fig. 1).…”

Section: Samplementioning

confidence: 99%

“…-V magnitudes are computed from the mean and standard deviation of all values reported to the AAVSO between 2015 July 10 and 2015 August 1. The K magnitudes are computed from 2MASS Ks (V1057 Cyg and V1515 Cyg) or fromSung et al (2013) (HBC 722), assuming the K-band flux has leveled out since 2013, as it has in the optical bands (source: AAVSO).…”

mentioning

confidence: 99%

TESTING THE BINARY TRIGGER HYPOTHESIS IN FUors

Green

Kraus

Rizzuto

et al. 2016

ApJ

View full text Add to dashboard Cite

We present observations of three FU Orionis objects (hereafter, FUors) with nonredundant aperturemask interferometry (NRM) at 1.59 µm and 2.12 µm that probe for binary companions on the scale of the protoplanetary disk that feeds their accretion outbursts. We do not identify any companions to V1515 Cyg or HBC 722, but we do resolve a close binary companion to V1057 Cyg that is at the diffraction limit (ρ = 58.3 ± 1.4 mas or 30 ± 5 AU) and currently much fainter than the outbursting star (∆K ′ = 3.34 ± 0.10 mag). Given the flux excess of the outbursting star, we estimate that the mass of the companion (M ∼ 0.25M ⊙ ) is similar to or slightly below that of the FUor itself, and therefore it resembles a typical T Tauri binary system. Our observations only achieve contrast limits of ∆K ′ ∼ 4 mag, and hence we are only sensitive to companions that were near or above the pre-outburst luminosity of the FUors. It remains plausible that FUor outbursts could be tied to the presence of a close binary companion. However, we argue from the system geometry and mass reservoir considerations that these outbursts are not directly tied to the orbital period (i.e., occurring at periastron passage), but instead must only occur infrequently.

show abstract

“…Here, we report the first X-ray detection of an FUor in the initial stages of its outburst. The recently erupting HBC 722 is the first and so far only FUor that has been monitored from its early outburst phase to the (presumably) main peak in all available wavelength bands (Dunham et al 2012;Sung et al 2013;Green et al 2013;Semkov et al 2014). We obtained three Xray observations during the initial rise of the optical light, during a subsequent minimum, and during the following second maximum.…”

Section: Introductionmentioning

confidence: 99%

X-ray emission from an FU Orionis star in early outburst: HBC 722

Liebhart

Güdel

Skinner

et al. 2014

A&A

View full text Add to dashboard Cite

Aims. We conducted the first X-ray observations of the newly erupting FU Ori-type outburst in HBC 722 (V2493 Cyg) with the aim to characterize its X-ray behavior and near-stellar environment during early outburst. Methods. We used data from the XMM-Newton and Chandra X-ray observatories to measure X-ray source temperatures and luminosities as well as the gas column densities along the line of sight toward the source. Results. We report a Chandra X-ray detection of HBC 722 with an X-ray luminosity of L X ≈ 4 × 10 30 ergs s −1 . The gas column density exceeds values expected from optical extinction and standard gas-to-dust ratios. We conclude that dust-free gas masses are present around the star, such as strong winds launched from the inner disk, or massive accretion columns. A tentative detection obtained by XMM-Newton two years earlier after an initial optical peak revealed a fainter X-ray source with only weak absorption.

show abstract

Near-Ir Photometric Study of the Fu Orionis Object HBC 722

Cited by 9 publications

References 24 publications

Diagnosing FU Ori-like Sources: The Parameter Space of Viscously Heated Disks in the Optical and Near-infrared

Diagnosing FU Ori-like Sources: The Parameter Space of Viscously Heated Disks in the Optical and Near-infrared

TESTING THE BINARY TRIGGER HYPOTHESIS IN FUors

X-ray emission from an FU Orionis star in early outburst: HBC 722

Contact Info

Product

Resources

About