Engineering topics

Wright, D. J.

Publications and source records attributed to Wright, D. J..

3 records

DOE OSTI2016

HATS-25B THROUGH HATS-30B: A HALF–DOZEN NEW INFLATED TRANSITING HOT JUPITERS FROM THE HATSOUTH SURVEY

We report six new inflated hot Jupiters (HATS-25b through HATS-30b) discovered using the HATSouth global network of automated telescopes. The planets orbit stars with V magnitudes in the range of ∼12–14 and have masses in the largely populated 0.5M{sub J}--0.7M{sub J} region of parameter space but span a wide variety of radii, from 1.17R{sub J} to 1.75R{sub J}. HATS-25b, HATS-28b, HATS-29b, and HATS-30b are typical inflated hot Jupiters (R{sub p}=1.17--1.26R{sub J}) orbiting G–type stars in short period (P = 3.2-4.6 days) orbits. However, HATS-26b (R{sub p}=1.75R{sub J}, P=3.3024 days) and HATS-27b (R{sub p}=1.50R{sub J}, P=4.6370 days) stand out as highly inflated planets orbiting slightly evolved F stars just after and in the turn–off points, respectively, which are among the least dense hot Jupiters, with densities of 0.153 g cm{sup −3} and 0.180 g cm{sup −3}, respectively. All the presented exoplanets but HATS-27b are good targets for future atmospheric characterization studies, while HATS-27b is a prime target for Rossiter—McLaughlin monitoring in order to determine its spin–orbit alignment given the brightness (V = 12.8) and stellar rotational velocity (vsin i≈9.3 km s{sup −1}) of the host star. These discoveries significantly increase the number of inflated hot Jupiters known, contributing to our understanding of the mechanism(s) responsible for hot Jupiter inflation.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2016

SPIN–ORBIT ALIGNMENT FOR THREE TRANSITING HOT JUPITERS: WASP-103b, WASP-87b, and WASP-66b

We have measured the sky-projected spin–orbit alignments for three transiting hot Jupiters, WASP-103b, WASP-87b, and WASP-66b, using spectroscopic measurements of the Rossiter–McLaughlin effect, with the CYCLOPS2 optical fiber bundle system feeding the UCLES spectrograph on the Anglo-Australian Telescope. The resulting sky-projected spin–orbit angles of λ = 3° ± 33°, λ = −8° ± 11°, and λ = −4° ± 22° for WASP-103b, WASP-87b, and WASP-66b, respectively, suggest that these three planets are likely on nearly aligned orbits with respect to their host star’s spin axis. WASP-103 is a particularly interesting system as its orbital distance is only 20% larger than its host star’s Roche radius and the planet likely experiences strong tidal effects. WASP-87 and WASP-66 are hot ( T {sub eff} = 6450 ± 120 K and T {sub eff} = 6600 ± 150 K, respectively) mid-F stars, making them similar to the majority of stars hosting planets on high-obliquity orbits. Moderate spin–orbit misalignments for WASP-103b and WASP-66b are consistent with our data, but polar and retrograde orbits are not favored for these systems.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2016

THREE PLANETS ORBITING WOLF 1061

We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf 1061 (GJ 628). We detect a 1.36 M{sub ⊕} minimum-mass planet with an orbital period P = 4.888 days (Wolf 1061b), a 4.25 M{sub ⊕} minimum-mass planet with orbital period P = 17.867 days (Wolf 1061c), and a likely 5.21 M{sub ⊕} minimum-mass planet with orbital period P = 67.274 days (Wolf 1061d). All of the planets are of sufficiently low mass that they may be rocky in nature. The 17.867 day planet falls within the habitable zone for Wolf 1061 and the 67.274 day planet falls just outside the outer boundary of the habitable zone. There are no signs of activity observed in the bisector spans, cross-correlation FWHMs, calcium H and K indices, NaD indices, or Hα indices near the planetary periods. We use custom methods to generate a cross-correlation template tailored to the star. The resulting velocities do not suffer the strong annual variation observed in the HARPS DRS velocities. This differential technique should deliver better exploitation of the archival HARPS data for the detection of planets at extremely low amplitudes.

79 ASTRONOMY AND ASTROPHYSICS↗