- ID:
- ivo://CDS.VizieR/J/A+A/615/A175
- Title:
- Solar system analogs with HARPS
- Short Name:
- J/A+A/615/A175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The assessment of the frequency of planetary systems reproducing the solar system's architecture is still an open problem in exoplanetary science. Detailed study of multiplicity and architecture is generally hampered by limitations in quality, temporal extension and observing strategy, causing difficulties in detecting low-mass inner planets in the presence of outer giant planets. We present the results of high-cadence and high-precision HARPS observations on 20 solar-type stars known to host a single long-period giant planet in order to search for additional inner companions and estimate the occurence rate f_p_ of scaled solar system analogues - in other words, systems featuring lower-mass inner planets in the presence of long-period giant planets. We carried out combined fits of our HARPS data with literature radial velocities using differential evolution MCMC to refine the literature orbital solutions and search for additional inner planets. We then derived the survey detection limits to provide preliminary estimates of f_p_. We generally find better constrained orbital parameters for the known planets than those found in the literature; significant updates can be especially appreciated on half of the selected planetary systems. While no additional inner planet is detected, we find evidence for previously unreported long-period massive companions in systems HD 50499 and HD 73267. We finally estimate the frequency of inner low mass (10-30M_{earth}_) planets in the presence of outer giant planets as f_p_<9.84% for P<150-days. Our preliminary estimate of f_p_ is significantly lower than the literature values for similarly defined mass and period ranges; the lack of inner candidate planets found in our sample can also be seen as evidence corroborating the inwards-migration formation model for super-Earths and mini-Neptunes. Our results also underline the need for high-cadence and high-precision followup observations as the key to precisely determine the occurence of solar system analogues.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/152/112
- Title:
- Solar-type stars from SDSS-III MARVELS. VI. HD 87646
- Short Name:
- J/AJ/152/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detections of a giant planet (MARVELS-7b) and a brown dwarf (BD) candidate (MARVELS-7c) around the primary star in the close binary system, HD87646. To the best of our knowledge, it is the first close binary system with more than one substellar circumprimary companion that has been discovered. The detection of this giant planet was accomplished using the first multi-object Doppler instrument (KeckET) at the Sloan Digital Sky Survey (SDSS) telescope. Subsequent radial velocity observations using the Exoplanet Tracker at the Kitt Peak National Observatory, the High Resolution Spectrograph at the Hobby Eberley telescope, the "Classic" spectrograph at the Automatic Spectroscopic Telescope at the Fairborn Observatory, and MARVELS from SDSS-III confirmed this giant planet discovery and revealed the existence of a long-period BD in this binary. HD87646 is a close binary with a separation of ~22 au between the two stars, estimated using the Hipparcos catalog and our newly acquired AO image from PALAO on the 200inch Hale Telescope at Palomar. The primary star in the binary, HD87646A, has T_eff_=5770+/-80K, logg=4.1+/-0.1, and [Fe/H]=-0.17+/-0.08. The derived minimum masses of the two substellar companions of HD87646A are 12.4+/-0.7M_Jup_ and 57.0+/-3.7M_Jup_. The periods are 13.481+/-0.001days and 674+/-4 days and the measured eccentricities are 0.05+/-0.02 and 0.50+/-0.02 respectively. Our dynamical simulations show that the system is stable if the binary orbit has a large semimajor axis and a low eccentricity, which can be verified with future astrometry observations.
- ID:
- ivo://CDS.VizieR/J/A+A/390/717
- Title:
- Solar Velocities of the Sun in 1989-99 (IRIS++)
- Short Name:
- J/A+A/390/717
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IRIS (International Research of Interior of the Sun) network has been operated continuously since July 1st 1989. To date, it has acquired more than a complete solar cycle of full-disk helioseismic data which has been used to constrain the structure and rotation of the deep solar interior. However, the duty cycle of the network data has never reached initial expectations. To improve this situation, several cooperations have been developed with teams collecting observations with similar instruments. This paper demonstrates that we are able to merge data from these different instruments in a consistent manner resulting in a very significant improvement in network duty cycle over more than one solar cycle initiating what we call the IRIS++ network.
- ID:
- ivo://CDS.VizieR/J/MNRAS/417/1823
- Title:
- Sombrero galaxy globular clusters
- Short Name:
- J/MNRAS/417/1823
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large sample of over 200 integrated-light spectra of confirmed globular clusters (GCs) associated with the Sombrero (M104) galaxy taken with the Deep Imaging Multi-Object Spectrograph (DEIMOS) instrument on the Keck telescope. A significant fraction of the spectra have signal-to-noise ratio levels high enough to allow measurements of GC metallicities using the method of Brodie & Huchra. We find a distribution of spectroscopic metallicities in the range -2.2<[Fe/H]<+0.1 that is bimodal, with peaks at [Fe/H]~-1.4 and -0.6. Thus, the GC system of the Sombrero galaxy, like a few other galaxies now studied in detail, reveals a bimodal spectroscopic metallicity distribution supporting the long-held belief that colour bimodality reflects two metallicity subpopulations. This further suggests that the transformation from optical colour to metallicity for old stellar populations, such as GCs, is not strongly non-linear. We also explore the radial and magnitude distribution with metallicity for GC subpopulations but small number statistics prevent any clear trends in these distributions.
- ID:
- ivo://CDS.VizieR/J/A+A/650/A39
- Title:
- SOPHIE and HARPS Young Nearby Stars - YNS
- Short Name:
- J/A+A/650/A39
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The search of close (a<~5au) giant planet (GP) companions with radial velocity (RV) around young stars and the estimate of their occurrence rates is important to constrain the migration timescales. Furthermore, this search will allow the giant planet occurrence rates to be computed at all separations via the combination with direct imaging techniques. The RV search around young stars is a challenge as they are generally faster rotators than older stars of similar spectral types and they exhibit signatures of magnetic activity (spots) or pulsation in their RV time series. Specific analyses are necessary to characterize, and possibly correct for, this activity. Our aim is to search for planets around young nearby stars and to estimate the GP occurrence rates for periods up to 1000 days. We used the SOPHIE spectrograph on the 1.93m telescope at the Haute-Provence Observatory to observe 63 A-M young (<400Myr) stars. We used our Spectroscopic data via Analysis of the Fourier Interspectrum Radial velocities (SAFIR) software to compute the RVs and other spectroscopic observables. We then combined this survey with the HARPS YNS survey to compute the companion occurrence rates on a total of 120 young A-M stars. Results. We report one new trend compatible with a planetary companion on HD 109647. We also report HD 105693 and HD 112097 as binaries, and we confirm the binarity of HD 2454, HD13531, HD 17250 A, HD 28945, HD 39587, HD 131156, HD 142229, HD 186704 A, and HD 195943. We constrained for the first time the orbital parameters of HD 195943 B. We refute the HD 13507 single brown dwarf (BD) companion solution and propose a double BD companion solution. Two GPs were previously reported from this survey in the HD 113337 system. Based on our sample of 120 young stars, we obtain a GP occurrence rate of 1^+2/2^_0/3_% for periods lower than 1000 days, and we obtain an upper limit on BD occurrence rate of 0.9^+2^_0.9_% in the same period range. We report a possible lack of close (P {in} [1; 1000] days) GPs around young FK stars compared to their older counterparts, with a confidence level of 90%.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A17
- Title:
- SOPHIE data of Gliese 411
- Short Name:
- J/A+A/625/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Periodic radial velocity variations in the nearby M-dwarf star Gl 411 are reported, based on measurements with the SOPHIE spectrograph. Current data do not allow us to distinguish between a 12.95-day period and its one-day alias at 1.08-days, but favour the former slightly. The velocity variation has an amplitude of 1.6m/s, making this the lowest-amplitude signal detected with SOPHIE up to now. We have performed a detailed analysis of the significance of the signal and its origin, including extensive simulations with both uncorrelated and correlated noise, representing the signal induced by stellar activity. The signal is significantly detected, and the results from all tests point to its planetary origin. Additionally, the presence of an additional acceleration in the velocity time series is suggested by the current data. On the other hand, a previously reported signal with a period of 9.9 days, detected in HIRES velocities of this star, is not recovered in the SOPHIE data. An independent analysis of the HIRES dataset also fails to unveil the 9.9-day signal. If the 12.95-day period is the real one, the amplitude of the signal detected with SOPHIE implies the presence of a planet, called Gl 411 b, with a minimum mass of around three Earth masses, orbiting its star at a distance of 0.079AU. The planet receives about 3.5 times the insolation received by Earth, which implies an equilibrium temperature between 256 and 350K, and makes it too hot to be in the habitable zone. At a distance of only 2.5pc, Gl 411 b, is the third closest low-mass planet detected to date. Its proximity to Earth will permit probing its atmosphere with a combination of high-contrast imaging and high-dispersion spectroscopy in the next decade.
- ID:
- ivo://CDS.VizieR/J/A+A/651/A11
- Title:
- SOPHIE radial velocities of 27 F/G stars
- Short Name:
- J/A+A/651/A11
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Distinguishing classes within substellar objects and understanding their formation and evolution need larger samples of substellar companions such as exoplanets, brown dwarfs, and low-mass stars. In this paper, we look for substellar companions using radial velocity surveys of FGK stars with the SOPHIE spectrograph at the Observatoire de Haute-Provence. We assign here the radial velocity variations of 27 stars to their orbital motion induced by low-mass companions. We also constrained their plane-of-the-sky motion using HIPPARCOS and Gaia Data Release 1 measurements, which constrain the true masses of some of these companions. We report the detection and characterization of six cool Jupiters, three brown dwarf candidates, and 16 low-mass stellar companions. We additionally update the orbital parameters of the low-mass star HD 8291 B, and we conclude that the radial velocity variations of HD 204277 are likely due to stellar activity despite resembling the signal of a giant planet. One of the new giant planets, BD+631405 b, adds to the population of highly eccentric cool Jupiters, and it is presently the most massive member. Two of the cool Jupiter systems also exhibit signatures of an additional outer companion. The orbital periods of the new companions span 30 days to 11.5 years, their masses 0.72M_Jup_ to 0.61M_{sun}_, and their eccentricities 0.04 to 0.88. These discoveries probe the diversity of substellar objects and low-mass stars, which will help constrain the models of their formation and evolution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/439/354
- Title:
- Sources around Tycho's Supernova 1572
- Short Name:
- J/MNRAS/439/354
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With archival and new Hubble Space Telescope observations, we have refined the space-velocity measurements of the stars in the central region of the remnant of Tycho's supernova (SN) 1572, one of the historical Galactic Type Ia supernova remnants (SNRs). We derived a proper motion for Tycho-G of (pmRAcosDE;pmDE) J2000.0 =(-2.63;,-3.98)+/-(0.06;,0.04)[formal errors] +/-(0.18;0.10)[expected errors]mas/yr. If the star were at the distance of the SNR (taken here to be 2.83kpc), its velocity would be V_b_=-51+/-1.5km/s. We also reconstruct the binary orbit that Tycho-G should have followed if it were the surviving companion of SN 1572. We redetermine the Ni abundance of this star and compare it with new abundance data from stars of the Galactic disc, finding that [Ni/Fe] is about 1.7{sigma} above the Galactic trend. From the high velocity of Tycho-G perpendicular to the Galactic plane (-90+/-3km/s<=V_b_<=-45+/-1km/s, for the allowed range of distances to the star), its metallicity and its Ni excess, we find the probability of it being a chance interloper to be P<~0.00037 at most. The projected rotational velocity of the star should be below current observational limits. The projected position of Tycho-G is, within the uncertainties, consistent with the centroid of the X-ray emission of Tycho's SNR; moreover, its brightness is generally consistent with the post-explosion evolution of the luminosity of an SN companion. Among the other 23 stars having V<22mag and located within 42-arcsec from the X-ray centroid, only 4 are at distances compatible with that of the SNR, and none of them shows any peculiarity. Therefore, if even Tycho-G is not the surviving companion of SN 1572, the absence of other viable candidates does favour the merging of two white dwarfs as the producer of the SN.
- ID:
- ivo://CDS.VizieR/J/A+A/597/A10
- Title:
- South Ecliptic Pole stars radial velocities
- Short Name:
- J/A+A/597/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an initial overview of the targets to be found in the 1-square-degree SEP region that was observed repeatedly by Gaia ever since its commissioning. In our representative sample, we identified one galaxy, six LMC S-stars, nine candidate chromospherically active stars, and confirmed the status of 18 LMC Carbon stars. A careful study of the 3471 epoch radial velocity measurements led us to identify 145 RV constant stars with radial velocities varying by less than 1km/s. Seventy-eight stars show significant RV scatter, while nine stars show a composite spectrum. As expected, the distribution of the RVs exhibits two main peaks that correspond to Galactic and LMC stars. By combining [Fe/H], and logg, estimates, and RV determinations, we identified 203 members of the LMC, while 51 more stars are candidate members.
- ID:
- ivo://CDS.VizieR/J/A+AS/125/329
- Title:
- Southern binary galaxies radial velocities
- Short Name:
- J/A+AS/125/329
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectrophotometry of a sample of 26 Southern binary galaxies. 17 pairs were confirmed to be physically associated with typical separation of 136h^-1^kpc. Pairs with velocity difference {DELTA}V>=600km/s are probably not physically bound. A comparison with field galaxies suggests that galaxies in pairs tend to have a younger population probably stimulated by tidal interaction. No correlation between the young population and projected separation was found. This table contains the quantities derived from the spectral data.
