HD 164492C: a rapidly rotating, Hα-bright, magnetic early B star associated with a 12.5 d spectroscopic binary

Wade, G. A.; Shultz, Matt; Sikora, J.; Bernier, M.; Rivinius, Thomas; Alécian, E.; Petit, Véronique; Grunhut, J.

doi:10.1093/mnras/stw2799

Cited by 23 publications

(19 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resulting distance from Gaia EDR3 parallaxes is much closer than previous measurements using spectroscopic parallaxes or extinction mapping. It agrees with the estimate of ∼1.22 kpc made using Gaia DR2 parallaxes by Wade et al (2017). As a comparison, also shown are the histogram of distances of Gaia EDR3 sources meeting the proper motion criterion, and having RUWE and σ π within the limit for our sample.…”

Section: Distance To the Trifid Nebulasupporting

confidence: 89%

The Young Stellar Population, Distance, and Cloud-Cloud Collision Induced Star Formation Scenario of the Trifid Nebula

Kalari

2021

Preprint

View full text Add to dashboard Cite

The Trifid Nebula is a young, nearby star-forming region where star formation is proposed to have been triggered by cloud-cloud collision (CCC), based on observations of molecular clouds. It offers a unique opportunity to test whether the CCC hypothesis is supported by the spatial distribution and star formation chronology of young stars.We present the first study of the optically visible pre-main sequence (PMS) population of the region using riHα imaging and Gaia astrometry. Combined with an analysis of young stellar objects (YSOs) using infrared imaging, we capture the spatial distribution and star formation chronology of the young stellar population. From the analysis, 15 Flat/Class I YSOs, 46 Class II YSOs, and 41 accreting PMS stars are identified (diskless/non-accreting sources are not included in the analysis). The distance based on Gaia parallaxes is ∼1250 pc, significantly closer than previously reported. The Class II YSOs and PMS stars (∼1.5 Myr old) are spread toward the edge of the molecular clouds. They are slightly younger than the estimated crossing time of ∼2.7 Myr and closer to the estimated dynamical age ∼0.85 Myr. Younger Class I YSOs are more concentrated spatially. There exists a cavity devoid of young stars where the two clouds overlap. This evidence suggests that the current generation of stars formed after the collision of two clouds ∼1 Myr ago, and this result can be corroborated using future spectroscopic studies.

show abstract

Section: Distance To the Trifid Nebulasupporting

confidence: 89%

The Young Stellar Population, Distance, and Cloud-Cloud Collision Induced Star Formation Scenario of the Trifid Nebula

Kalari

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…We speculate that the magnetic field has a large scale structure that is similar to a simple dipolar configuration and a stable configuration deduced by the long lifetime of the spot (≥ 2.5 yrs). Wade et al (2017) have found a strong magnetic field, on the order of a few kG, in HD 164492C1, which is an early B star similar to ρ Oph rotating in 1.36 days and part of a hierarchical system with other two A/Herbig Ae stars belonging to the Trifid nebula. However, one difference from ρ Oph is that the HD 164492 system is tighter than that of ρ Oph and the origin of the magnetic field in such objects could be associated with binarity and the stellar formation mechanism.…”

Section: Discussionmentioning

confidence: 98%

The early B-type star Rho Ophiuchi A is an X-ray lighthouse

Pillitteri

Wolk

Reale

et al. 2017

A&A

View full text Add to dashboard Cite

We present the results of a 140 ks XMM-Newton observation of the B2 star ρ Oph A. The star has exhibited strong X-ray variability: a cusp-shaped increase of rate, similar to that which we partially observed in 2013, and a bright flare. These events are separated in time by about 104 ks, which likely corresponds to the rotational period of the star (1.2 days). Time resolved spectroscopy of the X-ray spectra shows that the first event is caused by an increase of the plasma emission measure, while the second increase of rate is a major flare with temperatures in excess of 60 MK (kT ∼ 5 keV). From the analysis of its rise, we infer a magnetic field of ≥ 300 G and a size of the flaring region of ∼ 1.4 − 1.9 × 10 11 cm, which corresponds to ∼ 25% − 30% of the stellar radius. We speculate that either an intrinsic magnetism that produces a hot spot on its surface or an unknown low mass companion are the source of such X-rays and variability. A hot spot of magnetic origin should be a stable structure over a time span of ≥2.5 years, and suggests an overall large scale dipolar magnetic field that produces an extended feature on the stellar surface. In the second scenario, a low mass unknown companion is the emitter of X-rays and it should orbit extremely close to the surface of the primary in a locked spin-orbit configuration, almost on the verge of collapsing onto the primary. As such, the X-ray activity of the secondary star would be enhanced by its young age, and the tight orbit as in RS Cvn systems and ρ Oph would constitute an extreme system that is worthy of further investigation.

show abstract

“…The prototype of a hot magnetic star with a RRM is σ Ori E (Groote & Hunger 1997;Townsend, Owocki & Groote 2005). Several σ Ori E analogues since discovered are: δ Ori C (Leone et al 2010); HD 176582 (Bohlender & Monin 2011); HR 5907 (Grunhut et al 2012a); HR 7355 (Rivinius et al 2013); HD 23478 (Eikenberry et al 2014;Sikora et al 2015); HD 345439 (Eikenberry et al 2014;Wisniewski et al 2015;Hubrig et al 2017); HD 35502 (Sikora et al 2016); HD 164492C (Wade et al 2017).…”

mentioning

confidence: 99%

A combined multiwavelength VLA/ALMA/Chandra study unveils the complex magnetosphere of the B-type star HR5907

Leto

Trigilio

Oskinova

et al. 2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present new radio/millimeter measurements of the hot magnetic star HR 5907 obtained with the VLA and ALMA interferometers. We find that HR 5907 is the most radio luminous early type star in the cm-mm band among those presently known. Its multi-wavelength radio light curves are strongly variable with an amplitude that increases with radio frequency. The radio emission can be explained by the populations of the non-thermal electrons accelerated in the current sheets on the outer border of the magnetosphere of this fast rotating magnetic star. We classify HR 5907 as another member of the growing class of strongly magnetic fast rotating hot stars where the gyro-synchrotron emission mechanism efficiently operates in their magnetospheres. The new radio observations of HR 5907 are combined with archival X-ray data to study the physical condition of its magnetosphere. The X-ray spectra of HR 5907 show tentative evidence for the presence of non-thermal spectral component. We suggest that non-thermal X-rays originate a stellar X-ray aurora due to streams of non-thermal electrons impacting on the stellar surface. Taking advantage of the relation between the spectral indices of the X-ray power-law spectrum and the non-thermal electron energy distributions, we perform 3-D modeling of the radio emission for HR 5907. The wavelength-dependent radio light-curves probe magnetospheric layers at different heights above the stellar surface. A detailed comparison between simulated and observed radio light-curves leads us to conclude that the stellar magnetic field of HR 5907 is likely non-dipolar, providing further indirect evidence of the complex magnetic field topology of HR 5907.

show abstract

HD 164492C: a rapidly rotating, Hα-bright, magnetic early B star associated with a 12.5 d spectroscopic binary

Cited by 23 publications

References 43 publications

The Young Stellar Population, Distance, and Cloud-Cloud Collision Induced Star Formation Scenario of the Trifid Nebula

The Young Stellar Population, Distance, and Cloud-Cloud Collision Induced Star Formation Scenario of the Trifid Nebula

The early B-type star Rho Ophiuchi A is an X-ray lighthouse

A combined multiwavelength VLA/ALMA/Chandra study unveils the complex magnetosphere of the B-type star HR5907

Contact Info

Product

Resources

About