4 research outputs found
TOI-1416: A system with a super-Earth planet with a 1.07 d period
TOI-1416 (BD+42 2504, HIP 70705) is a V =10 late G- or early K-type dwarf star. TESS detected transits in its Sectors 16, 23, and 50 with a depth of about 455 ppm and a period of 1.07 days. Radial velocities (RVs) confirm the presence of the transiting planet TOI-1416 b, which has a mass of 3.48 ± 0.47 M• and a radius of 1.62 ± 0.08 R•, implying a slightly sub-Earth density of 4.500.83+0.99 g cm3. The RV data also further indicate a tentative planet, c, with a period of 27.4 or 29.5 days, whose nature cannot be verified due to strong suspicions of contamination by a signal related to the Moon s synodic period of 29.53 days. The nearly ultra-short-period planet TOI-1416 b is a typical representative of a short-period and hot (Teq ≈ 1570 K) super-Earth-like planet. A planet model of an interior of molten magma containing a significant fraction of dissolved water provides a plausible explanation for its composition, and its atmosphere could be suitable for transmission spectroscopy with JWST. The position of TOI-1416 b within the radius-period distribution corroborates the idea that planets with periods of less than one day do not form any special group. It instead implies that ultra-short-period planets belong to a continuous distribution of super-Earth-like planets with periods ranging from the shortest known ones up to ≈ 30 days; their period-radius distribution is delimited against larger radii by the Neptune Desert and by the period-radius valley that separates super-Earths from sub-Neptune planets. In the abundance of small, short-periodic planets, a notable plateau has emerged between periods of 0.6- 1.4 days, which is compatible with the low-eccentricity formation channel. For the Neptune Desert, its lower limits required a revision due to the increasing population of short-period planets; for periods shorter then 2 days, we establish a radius of 1.6 R• and a mass of 0.028 Mjup (corresponding to 8.9 M•) as the desert s lower limits. We also provide corresponding limits to the Neptune Desert against the planets insolation and effective temperatures
State of the Field: Extreme Precision Radial Velocities
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 measurement precision. The presentations and
discussion of key issues for instrumentation and data analysis and the workshop
recommendations for achieving this precision are summarized here.
Beginning with the HARPS spectrograph, technological advances for precision
radial velocity measurements have focused on building extremely stable
instruments. To reach still higher precision, future spectrometers will need to
produce 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
radial velocity community include distinguishing center of mass Keplerian
motion from photospheric velocities, 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.
Center of mass 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. Higher precision radial
velocity measurements are required to serve as a discovery technique for
potentially habitable worlds and to characterize detections from transit
missions. The future of exoplanet science has very different trajectories
depending on the precision that can ultimately be achieved with Doppler
measurements.Comment: 45 pages, 23 Figures, workshop summary proceeding