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Earth-mass exoplanets are difficult to detect. The Dispersed Matter Planet Project (DMPP) identifies stars that are likely to host the most detectable low-mass exoplanets. The star DMPP-3 (HD 42936) shows signs of circumstellar absorption, indicative of mass loss from ablating planets. Here, we report the radial velocity discovery of a highly eccentric 507 d binary companion and a hot super-Earth-mass planet in a 6.67 d orbit around the primary star. DMPP-3A is a solar-type star while DMPP-3B is just massive enough to fuse hydrogen. The binary, with semi-major axis 1.22 ± 0.02 au, is considerably tighter than others known to host planets orbiting only one of the component stars. The configuration of the DMPP-3 planetary system is rare and indicates dynamical interactions, though the evolutionary history is not entirely clear. DMPP-3A b is possibly the residual core of a giant planet precursor, consistent with the inferred circumstellar gas shroud. The third target of the Dispersed Matter Planet Project, DMPP-3, is an unusual binary system containing a solar-type star ablating a super-Earth-mass planet, along with a very low mass secondary.

Some highly irradiated close-in exoplanets orbit stars showing anomalously low stellar chromospheric emission. We attribute this deficit to absorption by circumstellar gas replenished by mass loss from ablating planets. Here we report statistics validating this hypothesis. Among ~3,000 nearby, bright, main-sequence stars, ~40 show depressed chromospheric emission indicative of undiscovered mass-losing planets. The Dispersed Matter Planet Project uses high-precision, high-cadence radial velocity (RV) measurements to detect these planets. We summarize results for two planetary systems (DMPP-1 and DMPP-3) and fully present observations revealing an M p  sin  i  = 0.469 M J planet in a 5.207 d orbit around the γ Doradus pulsator HD 11231 (DMPP-2). We have detected short-period planets wherever we have made more than 60 RV measurements, demonstrating that we have originated a very efficient method for detecting nearby compact planetary systems. These shrouded, ablating planetary systems may be a short-lived phase related to the Neptunian desert, that is, the dearth of intermediate-mass planets at short orbital periods. The circumstellar gas facilitates compositional analysis, allowing empirical exogeology in the cases of sublimating rocky planets. Dispersed Matter Planet Project discoveries will be important for establishing the empirical mass–radius–composition relationship(s) for low-mass planets. This Article provides an overview of the Dispersed Matter Planet Project, a programme to discover close-in exoplanets being ablated by their host stars by means of the stars’ anomalously low chromospheric emission. One example is presented here: DMPP-2 hosts a sub-Jupiter-mass planet around a γ Doradus pulsator.

The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of the art Doppler precision and identified the critical path challenges for reaching 10 cm s(-1) measurement precision. The presentations and discussion of key issues for instrumentation and data analysis and the workshop recommendations for achieving this bold precision are summarized here. Beginning with the High Accuracy Radial Velocity Planet Searcher spectrograph, technological advances for precision radial velocity (RV) measurements have focused on building extremely stable instruments. To reach still higher precision, future spectrometers will need to improve upon the state of the art, producing even higher fidelity spectra. This should be possible with improved environmental control, greater stability in the illumination of the spectrometer optics, better detectors, more precise wavelength calibration, and broader bandwidth spectra. Key data analysis challenges for the precision RV community include distinguishing center of mass (COM) Keplerian motion from photospheric velocities (time correlated noise) and the proper treatment of telluric contamination. Success here is coupled to the instrument design, but also requires the implementation of robust statistical and modeling techniques. COM velocities produce Doppler shifts that affect every line identically, while photospheric velocities produce line profile asymmetries with wavelength and temporal dependencies that are different from Keplerian signals. Exoplanets are an important subfield of astronomy and there has been an impressive rate of discovery over the past two decades. However, higher precision RV measurements are required to serve as a discovery technique for potentially habitable worlds, to confirm and characterize detections from transit missions, and to provide mass measurements for other space-based missions. The future of exoplanet science has very different trajectories depending on the precision that can ultimately be achieved with Doppler measurements.

Gravity is one of the most constant environmental factors across Earth’s evolution and all organisms are adapted to it. Consequently, spatial exploration has captured the interest in studying the biological changes that physiological alterations are caused by gravity. In the last two decades, epigenetics has explained how environmental cues can alter gene functions in organisms. Although many studies addressed gravity, the underlying biological and molecular mechanisms that occur in altered gravity for those epigenetics-related mechanisms, are mostly inexistent. The present study addressed the effects of hypergravity on development, behavior, gene expression, and most importantly, on the epigenetic changes in a worldwide animal model, the zebrafish ( Danio rerio ). To perform hypergravity experiments, a custom-centrifuge simulating the large diameter centrifuge (100 rpm ~ 3 g ) was designed and zebrafish embryos were exposed during 5 days post fertilization (dpf). Results showed a significant decrease in survival at 2 dpf but no significance in the hatching rate. Physiological and morphological alterations including fish position, movement frequency, and swimming behavior showed significant changes due to hypergravity. Epigenetic studies showed significant hypermethylation of the genome of the zebrafish larvae subjected to 5 days of hypergravity. Downregulation of the gene expression of three epigenetic-related genes ( dnmt1 , dnmt3 , and tet1 ), although not significant, was further observed. Taken altogether, gravity alterations affected biological responses including epigenetics in fish, providing a valuable roadmap of the putative hazards of living beyond Earth.

We describe a flexible data reduction package for high resolution cross-dispersed echelle data. This open-source package is developed in Python and includes optional GUIs for most of the steps. It does not require any pre-knowledge about the form or position of the echelle-orders. It has been tested on cross-dispersed echelle spectrographs between 13k and 115k resolution (bifurcated fiber-fed spectrogaph ESO-HARPS and single fiber-fed spectrograph TNT-MRES). HiFLEx can be used to determine radial velocities and is designed to use the TERRA package but can also control the radial velocity packages such as CERES and SERVAL to perform the radial velocity analysis. Tests on HARPS data indicates radial velocities results within 3 m s−1 of the literature pipelines without any fine tuning of extraction parameters.

ABSTRACT We present a method to optimize absorption cells for precise wavelength calibration in the near-infrared. We apply it to design and optimize methane isotopologue cells for precision radial velocity measurements in the K band. We also describe the construction and installation of two such cells for the CSHELL spectrograph at NASA's IRTF. We have obtained their high-resolution laboratory spectra, which we can then use in precision radial velocity measurements and which can also have other applications. In terms of obtainable RV precision, methane should outperform other proposed cells, such as the ammonia cell ( NH 3 14 ) recently demonstrated on CRIRES/VLT. The laboratory spectra of the ammonia and methane cells show strong absorption features in the H band that could also be exploited for precision Doppler measurements. We present spectra and preliminary radial velocity measurements obtained during our first-light run. These initial results show that a precision down to 20 - 30 m s - 1 can be obtained using a wavelength interval of only 5 nm in the K band and S/N ∼ 150. This supports the prediction that a precision down to a few meters per second can be achieved on late-M dwarfs using the new generation of NIR spectrographs, thus enabling the detection of terrestrial planets in their habitable zones. Doppler measurements in the NIR can also be used to mitigate the radial velocity jitter due to stellar activity, enabling more efficient surveys on young active stars.

Robertson et al . (Reports, 25 July 2014, p. 440) claimed that activity-induced variability is responsible for the Doppler signal of the proposed planet candidate GJ 581d. We point out that their analysis using periodograms of residual data is inappropriate and promotes inadequate tools. Because the claim challenges the viability of the method to detect exo-Earths, we encourage reanalysis and a deliberation on what the field-standard methods should be.

We are undertaking an astrometric search for gas giant planets and brown dwarfs orbiting nearby low-mass dwarf stars with the 2.5 m du Pont Telescope at the Las Campanas Observatory in Chile. We have built two specialized astrometric cameras, the Carnegie Astrometric Planet Search Cameras (CAPSCam-S and CAPSCam-N), using two Teledyne HAWAII-2RG HyViSI arrays, with the cameras’ design having been optimized for high-accuracy astrometry of M dwarf stars. We describe two independent CAPSCam data reduction approaches and present a detailed analysis of the observations to date of one of our target stars, NLTT 48256. Observations of NLTT 48256 taken since 2007 July with CAPSCam-S imply that astrometric accuracies of around 0.3 mashr-1 h r - 1 are achievable, sufficient to detect a Jupiter-mass companion orbiting 1 AU from a late M dwarf 10 pc away with a signal-to-noise ratio (S/N) of about 4. We plan to follow about 100 nearby (primarily within about 10 pc) low-mass stars, principally late M, L, and T dwarfs, for 10 yr or more, in order to detect very low-mass companions with orbital periods long enough to permit the existence of habitable, Earth-like planets on shorter-period orbits. These stars are generally too faint and red to be included in ground-based Doppler planet surveys, which are often optimized for FGK dwarfs. The smaller masses of late M dwarfs also yield correspondingly larger astrometric signals for a given mass planet. Our search will help to determine whether gas giant planets form primarily by core accretion or by disk instability around late M dwarf stars.

AU Microscopii (AU Mic) is the second closest pre-main-sequence star, at a distance of 9.79 parsecs and with an age of 22 million years 1 . AU Mic possesses a relatively rare 2 and spatially resolved 3 edge-on debris disk extending from about 35 to 210 astronomical units from the star 4 , and with clumps exhibiting non-Keplerian motion 5 – 7 . Detection of newly formed planets around such a star is challenged by the presence of spots, plage, flares and other manifestations of magnetic ‘activity’ on the star 8 , 9 . Here we report observations of a planet transiting AU Mic. The transiting planet, AU Mic b, has an orbital period of 8.46 days, an orbital distance of 0.07 astronomical units, a radius of 0.4 Jupiter radii, and a mass of less than 0.18 Jupiter masses at 3 σ confidence. Our observations of a planet co-existing with a debris disk offer the opportunity to test the predictions of current models of planet formation and evolution. A transiting planet with a period of about 8.5 days and a radius 0.4 times that of Jupiter is reported within the debris disk around the star AU Microscopii.

A small planet of at least 1.3 Earth masses is orbiting Proxima Centauri with a period of about 11.2 days, with the potential for liquid water on its surface. At a distance of 1.295 parsecs 1 , the red dwarf Proxima Centauri (α Centauri C, GL 551, HIP 70890 or simply Proxima) is the Sun’s closest stellar neighbour and one of the best-studied low-mass stars. It has an effective temperature of only around 3,050 kelvin, a luminosity of 0.15 per cent of that of the Sun, a measured radius of 14 per cent of the radius of the Sun 2 and a mass of about 12 per cent of the mass of the Sun. Although Proxima is considered a moderately active star, its rotation period is about 83 days (ref. 3 ) and its quiescent activity levels and X-ray luminosity 4 are comparable to those of the Sun. Here we report observations that reveal the presence of a small planet with a minimum mass of about 1.3 Earth masses orbiting Proxima with a period of approximately 11.2 days at a semi-major-axis distance of around 0.05 astronomical units. Its equilibrium temperature is within the range where water could be liquid on its surface 5 .