A Survey of CA II H and K Chromospheric Emission in Southern Solar-Type Stars

Henry, Todd J.; Soderblom, David R.; Donahue, R. A.; Baliunas, S. L.

doi:10.1086/117796

Cited by 435 publications

(621 citation statements)

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“…Stellar rotational periods are either taken from Saar & Osten (1997) or estimated using Eqs. (3) and (4) in Noyes et al (1984) and the Ca II H&K results from Henry et al (1996). Figure 18 displays the RV excess scatter plotted vs. P Rot , which shows a general increase in the excess scatter with shorter rotational periods.…”

Section: Activity Induced Rv Excess Scattermentioning

confidence: 95%

“…Table 1 summarizes all targets with their HR, HD and GJ catalogue number, spectral classification, V-magnitudes, distance in parsecs, chromospheric emission indices (log R / HK ) and their X-ray luminosity (L X ). Distances are based on the Hipparcos parallaxes (ESA (1997)), the log R / HK -values are taken from the survey of Ca II H&K emission in southern solar-type stars by Henry et al (1996) and the L X values are coming from the RASS (ROSAT All Sky Survey) results (Hünsch et al 1998(Hünsch et al , 1999. Chromospheric emission in the cores of the Ca II H&K lines and the X-ray luminosities serve as stellar activity indicators since increased chromospheric Ca II H&K and coronal X-ray emission is a common sign of active stars.…”

Section: The Target Samplementioning

confidence: 99%

“…Target list of the CES planet search program. HR, HD and GJ catalogue numbers, spectral type, visual magnitude V, distance in parsec (based on Hipparcos parallaxes), chromospheric emission index from Henry et al (1996) and X-ray luminosity L X from Hünsch et al (1998Hünsch et al ( , 1999 presented in this work all refer to the Long Camera configuration (R = 100 000) prior to this modification, which thus form a homogeneous data set.…”

Section: Observationsmentioning

confidence: 99%

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The planet search program at the ESO Coudé Echelle spectrometer

Endl

Kürster

Els

et al. 2002

A&A

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Abstract. We present the complete results of the planet search program carried out at the ESO Coudé Echelle Spectrometer (CES) on La Silla, using the Long Camera from Nov. 1992 to April 1998. The CES survey has monitored 37 late-type (F8V -M5V) stars in the southern hemisphere for variations in their differential radial velocities (RV) in order to detect Doppler reflex motions caused by planetary companions. This led to the discovery of the first extrasolar planet in an Earth-like orbit around the young (ZAMS) and active G0V star ι Horologii . Here we present the RV results for all survey stars and perform a statistical examination of the whole data-set. Each star is tested for RV variability, RV trends (linear and non-linear) and significant periodic signals. β Hyi and Ind are identified as long-term, low-amplitude RV variables. Furthermore, for 30 CES survey stars we determine quantitative upper mass-limits for giant planets based on our long-term RV results. We find that the CES Long Camera survey would have detected short-period ("51 Peg-type") planets around all 30 stars but no planets with m sin i < 1 M Jup at orbital separations larger than 2 AU. Finally, we demonstrate that the CES planet search can be continued without applying velocity corrections to the RV results coming from the currently installed Very Long Camera at the CES.

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Section: Activity Induced Rv Excess Scattermentioning

confidence: 95%

Section: The Target Samplementioning

confidence: 99%

Section: Observationsmentioning

confidence: 99%

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The planet search program at the ESO Coudé Echelle spectrometer

Endl

Kürster

Els

et al. 2002

A&A

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“…Stellar ages were determined according to (1) stellar luminosity (Lang 1992), or to (2) chromospheric activity (Henry et al 1996, Donahue 1993, (3) taken from Lauchame (1999) or (4) …”

Section: Table Captionsmentioning

confidence: 99%

Ultraviolet radiation constraints around the circumstellar habitable zones

Buccino

Lemarchand

Mauas

2006

Icarus

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Ultraviolet radiation is known to inhibit photosynthesis, induce DNA destruction and cause damage to a wide variety of proteins and lipids. In particular, UV radiation between 200-300 nm becomes energetically very damaging to most of the terrestrial biological systems. On the other hand, UV radiation is usually considered one of the most important energy source on the primitive Earth for the synthesis of many biochemical compounds and, therefore, essential for several biogenesis processes. In this work, we use these properties of the UV radiation to define the boundaries of an ultraviolet habitable zone. We also analyze the evolution of the UV habitable zone during the main sequence stage of the star.We apply these criteria to study the UV habitable zone for those extrasolar planetary systems that were observed by the International Ultraviolet Explorer (IUE). We analyze the possibility that extrasolar planets and moons could be suitable for life, according to the UV constrains presented in this work and other accepted criteria of habitability (liquid water, orbital stability, etc.).

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“…We study the tidal distortion of the primary star, the reflection effect and the effect of starspots on the radial-velocity solution. Henry et al (1996) note that ζ TrA is an active star from the H and K flux. However our recent spectra (2006) show negligible chromospheric emission.…”

Section: Introductionmentioning

confidence: 94%

An Investigation of the Small Eccentricity in the Spectroscopic Binary System ζ TrA

2006

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Abstract.The orbital eccentricity of the SB1 system ζ TrA (S.T. F9V, P ∼ 13 d) was found by Skuljan et al. (2004) to be e = 0.01398±0.00019. Lucy (2005) devised a statistical test of the significance of this result, based on the amplitude and phase of the third harmonic in the Fourier analysis of the radial velocity data, and concluded that the non-zero eccentricity measured does not arise from a slightly eccentric Keplerian orbit, but from proximity effects in the binary. He therefore believes a circular orbit should be assigned to this system. In this paper we investigate one possible proximity effect, namely the tidal distortion of the primary star, such that the measured Doppler shift does not accurately indicate the centre of mass radial velocity of the star as a whole. The code of Wilson & Devinney (2003) was used to model the tidal distortion of the measured radial velocities, assuming a range of possible secondary masses, corresponding to M-dwarf companions. The result is that even for the lowest possible mass secondary of 0.09M with sin i = 1 (this gives the greatest tidal distortion, as it is closest to the primary) there is no significant effect on the radial velocities (the differences are of order 1 m s −1 as a result of the tidal effects). Similar negligible tidal effects arise using a white dwarf companion. We note that the difference between a circular orbit and the observations amounts to as much as 140 m s −1 at some phases, which is essentially the amplitude of the second harmonic in the data. Our conclusion is that this strong and highly significant second harmonic is most probably the result of a small orbital eccentricity as reported by Skuljan et al. (2004). We note that the observed third harmonic according to Lucy (2005) has an amplitude of only 5.2 ± 2.0 m s −1 , which is just over twice the error bar of its measurement, and that the predicted third harmonic for an eccentric orbit is only 1.6 m s −1 .

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A Survey of CA II H and K Chromospheric Emission in Southern Solar-Type Stars

Cited by 435 publications

References 1 publication

The planet search program at the ESO Coudé Echelle spectrometer

The planet search program at the ESO Coudé Echelle spectrometer

Ultraviolet radiation constraints around the circumstellar habitable zones

An Investigation of the Small Eccentricity in the Spectroscopic Binary System ζ TrA

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