- ID:
- ivo://CDS.VizieR/J/A+A/575/A119
- Title:
- HARPS RV and stellar activity
- Short Name:
- J/A+A/575/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Planetary companions of a fixed mass induce reflex motions with a larger amplitude around lower-mass stars, which adds to making M dwarfs excellent targets for extra-solar planet searches. The most recent velocimeters with a stability of can detect very low-mass planets out to the habitable zone of these stars. Low-mass small planets are abundant around M dwarfs, and most of the known potentially habitable planets orbit one of these cool stars. Our M-dwarf radial velocity monitoring with HARPS on the ESO 3.6m telescope at La Silla observatory makes a major contribution to this sample. We present here dense radial velocity (RV) time series for three M dwarfs observed over ~five years: GJ 3293 (0.42M_{sun}_), GJ 3341 (0.47M_{sun}_), and GJ 3543 (0.45M_{sun}_). We extracted these RVs through minimum chi^2^ -matching of each spectrum against a stack of all observed spectra for the same star that has a high S/N ratio. We then compared potential orbital signals against several stellar activity indicators to distinguish the Keplerian variations induced by planets from the spurious signals that result from rotational modulation of stellar surface inhomogeneities and from activity cycles.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/512/A48
- Title:
- HARPS RV curves of HD125612, HD215497, HIP5158
- Short Name:
- J/A+A/512/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the detections of three multiple systems within the HARPS volume-limited sample. Among the six planets discussed in this paper we have identified a "super-Earth" planet with a minimum mass of 6.6M_{Earth}_ and a "Neptune" planet with minimum mass of 18M_{Earth}_, both orbiting their parent stars within a distance of 0.05AU and a period of approximately four days. These detections strengthen the argument that low-mass planets are primarily found in multiple-planetary systems.
- ID:
- ivo://CDS.VizieR/J/A+A/535/A54
- Title:
- HARPS search for extra-solar planets. XXIX
- Short Name:
- J/A+A/535/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJS/200/15
- Title:
- HARPS-TERRA project. I.
- Short Name:
- J/ApJS/200/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Doppler spectroscopy has uncovered or confirmed all the known planets orbiting nearby stars. Two main techniques are used to obtain precision Doppler measurements at optical wavelengths. The first approach is the gas cell method, which consists of least-squares matching of the spectrum of iodine imprinted on the spectrum of the star. The second method relies on the construction of a stabilized spectrograph externally calibrated in wavelength. The most precise stabilized spectrometer in operation is the High Accuracy Radial velocity Planet Searcher (HARPS), operated by the European Southern Observatory in La Silla Observatory, Chile. The Doppler measurements obtained with HARPS are typically obtained using the cross-correlation function (CCF) technique. This technique consists of multiplying the stellar spectrum by a weighted binary mask and finding the minimum of the product as a function of the Doppler shift. It is known that CCF is suboptimal in exploiting the Doppler information in the stellar spectrum. Here we describe an algorithm to obtain precision radial velocity measurements using least-squares matching of each observed spectrum to a high signal-to-noise ratio template derived from the same observations. This algorithm is implemented in our software HARPS-TERRA (Template-Enhanced Radial velocity Re-analysis Application). New radial velocity measurements on a representative sample of stars observed by HARPS are used to illustrate the benefits of the proposed method. We show that, compared with CCF, template matching provides a significant improvement in accuracy, especially when applied to M dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/523/A15
- Title:
- HARPS XXIII: RV data for the 8 targets
- Short Name:
- J/A+A/523/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present our HARPS radial-velocity data for eight low-activity solar-type stars belonging to the HARPS volume-limited sample: HD6718, HD8535, HD28254, HD290327, HD43197, HD44219, HD148156, and HD156411. Keplerian fits to these data reveal the presence of low-mass companions around these targets. With minimum masses ranging from 0.58 to 2.54M_{Jup}_, these companions are in the planetary mass domain. The orbital periods of these planets range from slightly less than one to almost seven years. The eight orbits presented in this paper exhibit a wide variety of eccentricities: from 0.08 to above 0.8.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A109
- Title:
- HARPS XXXI. The M-dwarf sample
- Short Name:
- J/A+A/549/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Searching for planets around stars with different masses helps us to assess the outcome of planetary formation for different initial conditions. The low-mass M dwarfs are also the most frequent stars in our Galaxy and potentially therefore, the most frequent planet hosts. We present observations of 102 southern nearby M dwarfs, using a fraction of our guaranteed time on the ESO/HARPS spectrograph. We observed for 460 h and gathered 1965 precise (~1-3m/s) radial velocities (RVs), spanning the period from Feb. 11, 2003 to Apr. 1, 2009.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/59
- Title:
- HAT-P-32 and HAT-P-33 follow-up
- Short Name:
- J/ApJ/742/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of two exoplanets transiting high-jitter stars. HAT-P-32b orbits the bright V=11.289 late-F-early-G dwarf star GSC 3281-00800, with a period P=2.150008+/-0.000001d. The stellar and planetary masses and radii depend on the eccentricity of the system, which is poorly constrained due to the high-velocity jitter (~80m/s). Assuming a circular orbit, the star has a mass of 1.16+/-0.04M_{sun}_ and radius of 1.22+/-0.02R_{sun}_, while the planet has a mass of 0.860+/-0.164M_J_ and a radius of 1.789+/-0.025R_J_. The second planet, HAT-P-33b, orbits the bright V=11.188 late-F dwarf star GSC 2461-00988, with a period P=3.474474+/-0.000001d. As for HAT-P-32, the stellar and planetary masses and radii of HAT-P-33 depend on the eccentricity, which is poorly constrained due to the high jitter (~50m/s). In this case, spectral line bisector spans (BSs) are significantly anti-correlated with the radial velocity residuals, and we are able to use this correlation to reduce the residual rms to ~35m/s. We find that the star has a mass of 1.38+/-0.04M_{sun}_ and a radius of 1.64+/-0.03R_{sun}_ while the planet has a mass of 0.762+/-0.101M_J_ and a radius of 1.686+/-0.045R_J_ for an assumed circular orbit. Due to the large BS variations exhibited by both stars we rely on detailed modeling of the photometric light curves to rule out blend scenarios. Both planets are among the largest radii transiting planets discovered to date.
- ID:
- ivo://CDS.VizieR/J/ApJ/726/52
- Title:
- HAT-P-18 and HAT-P-19 follow-up
- Short Name:
- J/ApJ/726/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of two new transiting extrasolar planets. HAT-P-18b orbits the V=12.759 K2 dwarf star GSC 2594-00646, with a period P=5.508023+/-0.000006 days, transit epoch T_c_=2454715.02174+/-0.00020(BJD), and transit duration 0.1131+/-0.0009 days. The host star has a mass of 0.77+/-0.03M_{sun}_, radius of 0.75+/-0.04R_{sun}_, effective temperature 4803+/-80K, and metallicity [Fe/H]=+0.10+/-0.08. The planetary companion has a mass of 0.197+/-0.013M_J_ and radius of 0.995+/-0.052R_J_, yielding a mean density of 0.25+/-0.04g/cm^3^. HAT-P-19b orbits the V=12.901 K1 dwarf star GSC 2283-00589, with a period P=4.008778+/-0.000006 days, transit epoch T_c_=2455091.53417+/-0.00034(BJD), and transit duration 0.1182+/-0.0014 days. The host star has a mass of 0.84+/-0.04M_{sun}_, radius of 0.82+/-0.05R_{sun}_, effective temperature 4990+/-130K, and metallicity [Fe/H]=+0.23+/-0.08. The planetary companion has a mass of 0.292+/-0.018M_J_ and radius of 1.132+/-0.072R_J_, yielding a mean density of 0.25+/-0.04g/cm^3^. The radial velocity residuals for HAT-P-19 exhibit a linear trend in time, which indicates the presence of a third body in the system. Comparing these observations with theoretical models, we find that HAT-P-18b and HAT-P-19b are each consistent with a hydrogen-helium-dominated gas giant planet with negligible core mass. HAT-P-18b and HAT-P-19b join HAT-P-12b and WASP-21b in an emerging group of low-density Saturn-mass planets, with negligible inferred core masses. However, unlike HAT-P-12b and WASP-21b, both HAT-P-18b and HAT-P-19b orbit stars with super-solar metallicity.
- ID:
- ivo://CDS.VizieR/J/ApJ/733/116
- Title:
- HAT-P-28 and HAT-P-29 photometry
- Short Name:
- J/ApJ/733/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of two transiting exoplanets. HAT-P-28b orbits a V=13.03 G3 dwarf star with a period P=3.2572 days and has a mass of 0.63+/-0.04M_J_ and a radius of 1.21^+0.11^_-0.08_R_J_ yielding a mean density of 0.44+/-0.09g/cm^3^. HAT-P-29b orbits a V=11.90 F8 dwarf star with a period P=5.7232 days and has a mass of 0.78^+0.08^_-0.04_M_J_ and a radius of 1.11^+0.14^_-0.08_R_J_ yielding a mean density of 0.71+/-0.18g/cm^3^. We discuss the properties of these planets in the context of other known transiting planets
- ID:
- ivo://CDS.VizieR/J/A+A/604/L4
- Title:
- HAT-P-4 and TYC 2569-744-1 abundances and spectra
- Short Name:
- J/A+A/604/L4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore condensation temperature Tc trends and the Li content in the binary system HAT-P-4, to study the possible chemical signature of planet formation. The star HAT-P-4 hosts a hot Jupiter planet detected by transits, while its stellar companion does not have any detected planets. We derived the fundamental parameters and abundances using the differential method. HAT-P-4 is found to be about 0.1dex more metal rich than its companion; it is enhanced in refractory elements and presents a higher Lithium content. We propose a scenario of a possible rocky planet engulfment in HAT-P-4, which explains the higher metallicity, the higher Li content, and the negative Tc trend we detected.
