Hot Jupiters and Hot Spots: The Short‐ and Long‐Term Chromospheric Activity on Stars with Giant Planets

Shkolnik, Evgenya L.; Walker, G. A. H.; Bohlender, D.; Gu, Pin-Gao; Kürster, M.

doi:10.1086/428037

Cited by 265 publications

(345 citation statements)

References 63 publications

Supporting

Mentioning

317

Contrasting

Order By: Relevance

“…Shkolnik et al (2005) appeared to confirm the result, and to find a similar effect in the υ And system. Shkolnik et al (2008) found the detections of these signals difficult to reproduce, leading them to speculate that the effect has an "on/off nature" (see Figure 2).…”

Section: Orbitally Modulated Activitysupporting

confidence: 57%

Magnetism and activity of planet hosting stars

Wright¹

2015

Proc. IAU

View full text Add to dashboard Cite

Abstract. The magnetic activity levels of planet host stars may differ from that of stars not known to host planets in several ways. Hot Jupiters may induce activity in their hosts through magnetic interactions, or through tidal interactions by affecting their host's rotation or convection. Measurements of photospheric, chromospheric, or coronal activity might then be abnormally high or low compared to control stars that do not host hot Jupiters, or might be modulated at the planet's orbital period. Such detections are complicated by the small amplitude of the expected signal, by the fact that the signals may be transient, and by the difficulty of constructing control samples due to exoplanet detection biases and the uncertainty of field star ages. We review these issues, and discuss avenues for future progress in the field.

show abstract

Section: Orbitally Modulated Activitysupporting

confidence: 57%

Magnetism and activity of planet hosting stars

Wright¹

2015

Proc. IAU

View full text Add to dashboard Cite

show abstract

“…Planet-induced activity through magnetic coupling (e.g. Shkolnik et al 2005) should be an alternative explanation of the correlation, but here it is not a very attractive one: the inner planet is at least as massive as the hypothetical 35-day planet and would, at least naively, be expected to have stronger interactions with the magnetosphere of GJ 674. The 4.69-day period, however, is only seen in the radial velocity signal, and it has no photometric or chromospheric counterpart.…”

Section: Planets Vs Activitymentioning

confidence: 94%

The HARPS search for southern extra-solar planets

Bonfils¹,

Mayor

Delfosse

et al. 2007

A&A

249

257

View full text Add to dashboard Cite

AstrophysicsThe HARPS search for southern extra-solar planets X. A m sin i = 11 M ⊕ planet around the nearby spotted M dwarf GJ 674 , ABSTRACTContext. How planet properties depend on stellar mass is a key diagnostic of planetary formation mechanisms. Aims. This motivates planet searches around stars that are significantly more massive or less massive than the Sun, and in particular our radial velocity search for planets around very low-mass stars. Methods. As part of that program, we obtained measurements of GJ 674, an M 2.5 dwarf at d = 4.5 pc. These measurements have dispersion much in excess of their internal errors. An intensive observing campaign demonstrates that the excess dispersion is due to two superimposed coherent signals, with periods of 4.69 and 35 days. Results. These data are described well by a 2-planet Keplerian model where each planet has a ∼11 M ⊕ minimum mass. A careful analysis of the (low-level) magnetic activity of GJ 674, however, demonstrates that the 35-day period coincides with the stellar rotation period. This signal therefore originates in a spot inhomogeneity modulated by stellar rotation. The 4.69-day signal, on the other hand, is caused by a bona-fide planet, GJ 674b. Conclusions. Its detection adds to the growing number of Neptune-mass planets around M-dwarfs and reinforces the emerging conclusion that this mass domain is much more populated than the Jovian mass range. We discuss the metallicity distributions of M dwarf with and without planets and find a low 11% probability that they are drawn from the same parent distribution. Moreover, we find tentative evidence that the host star metallicity correlates with the total mass of their planetary system.

show abstract

“…It has been speculated that similar effects, albeit on a weaker scale, may occur for stars with Hot Jupiters (Cuntz et al 2000;Lanza 2008). Observational studies have been performed on individual systems (Shkolnik et al 2005(Shkolnik et al , 2008Pillitteri et al 2011;Miller et al 2012) as well as on larger samples of planet-hosting stars (Kashyap et al 2008;Poppenhaeger et al 2010;Shkolnik 2013), finding weak correlations of stellar activity with the presence of Hot Jupiters. Indications for higher v sin i values have also been reported (Pont 2009) for systems with Hot Jupiters compared with systems hosting smaller or more distant planets, NASA Sagan Fellow yielding first indications of a tidal influence of exoplanets on their host stars.…”

Section: Introductionmentioning

confidence: 99%

Indications for an influence of hot Jupiters on the rotation and activity of their host stars

Poppenhaeger

Wolk

2014

A&A

126

121

View full text Add to dashboard Cite

Context. The magnetic activity of planet-hosting stars is an important factor for estimating the atmospheric stability of close-in exoplanets and the age of their host stars. It has long been speculated that close-in exoplanets can influence the stellar activity level. However, testing for tidal or magnetic interaction effects in samples of planet-hosting stars is difficult because stellar activity hinders exoplanet detection, so that stellar samples with detected exoplanets show a bias toward low activity for small exoplanets. Aims. We aim to test whether exoplanets in close orbits influence the stellar rotation and magnetic activity of their host stars. Methods. We developed a novel approach to test for systematic activity-enhancements in planet-hosting stars. We use wide (several 100 AU) binary systems in which one of the stellar components is known to have an exoplanet, while the second stellar component does not have a detected planet and therefore acts as a negative control. We use the stellar coronal X-ray emission as an observational proxy for magnetic activity and analyze observations performed with Chandra and XMM-Newton. Results. We find that in two systems for which strong tidal interaction can be expected the planet-hosting primary displays a much higher magnetic activity level than the planet-free secondary. In three systems for which weaker tidal interaction can be expected the activity levels of the two stellar components agree with each other. Conclusions. Our observations indicate that the presence of Hot Jupiters may inhibit the spin-down of host stars with thick outer convective layers. Possible causes for this effect include a transfer of angular momentum from the planetary orbit to the stellar rotation through tidal interaction, or differences during the early evolution of the system, where the host star may decouple from the protoplanetary disk early because of a gap opened by the forming Hot Jupiter.

show abstract

Hot Jupiters and Hot Spots: The Short‐ and Long‐Term Chromospheric Activity on Stars with Giant Planets

Cited by 265 publications

References 63 publications

Magnetism and activity of planet hosting stars

Magnetism and activity of planet hosting stars

The HARPS search for southern extra-solar planets

Indications for an influence of hot Jupiters on the rotation and activity of their host stars

Contact Info

Product

Resources

About