We study the possibility of using CsINa scintillators as an advantageous target for the detection of coherent elastic neutrino-nucleus scattering (CENNS), using the neutrino emissions from the SNS ...spallation source at Oak Ridge National Laboratory. The response of this material to low-energy nuclear recoils like those expected from this process is characterized. Backgrounds are studied using a 2kg low-background prototype crystal in a dedicated radiation shield. The conclusion is that a planned 14kg detector should measure approximately 550 CENNS events per year above a demonstrated ~7keVnr low-energy threshold, with a signal-to-background ratio sufficient for a first measurement of the CENNS cross-section. The cross-section for the Pb208(νe,e−)Bi208 reaction, of interest for future supernova neutrino detection, can be simultaneously obtained.
We report the discovery of four relatively massive (2-7 M J) transiting extrasolar planets. HAT-P-20b orbits the moderately bright V = 11.339 K3 dwarf star GSC 1910-00239 on a circular orbit, with a ...period P = 2.875317 ? 0.000004 days, transit epoch Tc = 2455080.92661 ? 0.00021 (BJDUTC), and transit duration 0.0770 ? 0.0008 days. The host star has a mass of 0.76 ? 0.03 M , radius of 0.69 ? 0.02 R , effective temperature 4595 ? 80 K, and metallicity Fe/H = +0.35 ? 0.08. The planetary companion has a mass of 7.246 ? 0.187 M J and a radius of 0.867 ? 0.033 R J yielding a mean density of 13.78 ? 1.50 g cm--3. HAT-P-21b orbits the V = 11.685 G3 dwarf star GSC 3013-01229 on an eccentric (e = 0.228 ? 0.016) orbit, with a period P = 4.124481 ? 0.000007 days, transit epoch Tc = 2454996.41312 ? 0.00069, and transit duration 0.1530 ? 0.0027 days. The host star has a mass of 0.95 ? 0.04 M , radius of 1.10 ? 0.08 R , effective temperature 5588 ? 80 K, and metallicity Fe/H = +0.01 ? 0.08. The planetary companion has a mass of 4.063 ? 0.161 M J and a radius of 1.024 ? 0.092 R J yielding a mean density of 4.68+1.59 -- 0.99 g cm--3. HAT-P-21b is a borderline object between the pM and pL class planets, and the transits occur near apastron. HAT-P-22b orbits the bright V = 9.732 G5 dwarf star HD 233731 on a circular orbit, with a period P = 3.212220 ? 0.000009 days, transit epoch Tc = 2454930.22001 ? 0.00025, and transit duration 0.1196 ? 0.0014 days. The host star has a mass of 0.92 ? 0.03 M , radius of 1.04 ? 0.04 R , effective temperature 5302 ? 80 K, and metallicity Fe/H = +0.24 ? 0.08. The planet has a mass of 2.147 ? 0.061 M J and a compact radius of 1.080 ? 0.058 R J yielding a mean density of 2.11+0.40 -- 0.29 g cm--3. The host star also harbors an M-dwarf companion at a wide separation. Finally, HAT-P-23b orbits the V = 12.432 G0 dwarf star GSC 1632-01396 on a close to circular orbit, with a period P = 1.212884 ? 0.000002 days, transit epoch Tc = 2454852.26464 ? 0.00018, and transit duration 0.0908 ? 0.0007 days. The host star has a mass of 1.13 ? 0.04 M , radius of 1.20 ? 0.07 R , effective temperature 5905 ? 80 K, and metallicity Fe/H = +0.15 ? 0.04. The planetary companion has a mass of 2.090 ? 0.111 M J and a radius of 1.368 ? 0.090 R J yielding a mean density of 1.01 ? 0.18 g cm--3. HAT-P-23b is an inflated and massive hot Jupiter on a very short period orbit, and has one of the shortest characteristic infall times (7.5+2.9 -- 1.8 Myr) before it gets engulfed by the star.
We report the discovery of HAT-P-26b, a transiting extrasolar planet orbiting the moderately bright V = 11.744 K1 dwarf star GSC 0320--01027, with a period P = 4.234516 ? 0.000015 days, transit epoch ...Tc = 2455304.65122 ? 0.00035 (BJD; Barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time (UTC)), and transit duration 0.1023 ? 0.0010 days. The host star has a mass of 0.82 ? 0.03 M , radius of 0.79+0.10 --0.04 R , effective temperature 5079 ? 88 K, and metallicity Fe/H = -0.04 ? 0.08. The planetary companion has a mass of 0.059 ? 0.007 M J, and radius of 0.565+0.072 --0.032 R J yielding a mean density of 0.40 ? 0.10 g cm-3. HAT-P-26b is the fourth Neptune-mass transiting planet discovered to date. It has a mass that is comparable to those of Neptune and Uranus, and slightly smaller than those of the other transiting Super-Neptunes, but a radius that is ~65% larger than those of Neptune and Uranus, and also larger than those of the other transiting Super-Neptunes. HAT-P-26b is consistent with theoretical models of an irradiated Neptune-mass planet with a 10 M {circled plus} heavy element core that comprises 50% of its mass with the remainder contained in a significant hydrogen-helium envelope, though the exact composition is uncertain as there are significant differences between various theoretical models at the Neptune-mass regime. The equatorial declination of the star makes it easily accessible to both Northern and Southern ground-based facilities for follow-up observations.
We report the discovery of HAT-P-25b, a transiting extrasolar planet orbiting the V = 13.19 G5 dwarf star GSC 1788-01237, with a period P = 3.652836 + or - 0.000019 days, transit epoch Tc = ...2455176.85173 + or - 0.00047 (BJD-barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time, UTC), and transit duration 0.1174 + or - 0.0017 days. The host star has amass of 1.01 + or - 0.03 M radius of (ProQuest: Formulae and/or non-USASCII text omitted) R effective temperature 5500 + or - 80 K, and metallicity Fe/H = +0.31 + or - 0.08. The planetary companion has a mass of 0.567 + or - 0.022 M sub(J) and radius of (ProQuest: Formulae and/or non-USASCII text omitted) R sub(J) yielding a mean density of 0.42 + or - 0.07 g cm super(-3).
We report the discovery of HAT-P-27b, an exoplanet transiting the moderately bright G8 dwarf star GSC 0333-00351 (V = 12.214). The orbital period is 3.039586 ? 0.000012 days, the reference epoch of ...transit is 2455186.01879 ? 0.00054 (BJD), and the transit duration is 0.0705 ? 0.0019 days. The host star with its effective temperature 5300 ? 90 K is somewhat cooler than the Sun and is more metal-rich with a metallicity of +0.29 ? 0.10. Its mass is 0.94 ? 0.04 M and radius is 0.90+0.05 -- 0.04 R . For the planetary companion we determine a mass of 0.660 ? 0.033 M J and radius of 1.038+0.077 -- 0.058 R J. For the 30 known transiting exoplanets between 0.3 M J and 0.8 M J, a negative correlation between host star metallicity and planetary radius and an additional dependence of planetary radius on equilibrium temperature are confirmed at a high level of statistical significance.
We report the discovery of HAT-P-24b, a transiting extrasolar planet orbiting the moderately bright V = 11.818 F8 dwarf star GSC 0774--01441, with a period P = 3.3552464 ? 0.0000071 days, transit ...epoch Tc = 2455216.97669 ? 0.00024 (BJD)11, and transit duration 3.653 ? 0.025 hr. The host star has a mass of 1.191 ? 0.042 M , radius of 1.317 ? 0.068 R , effective temperature 6373 ? 80 K, and a low metallicity of Fe/H = -0.16 ? 0.08. The planetary companion has a mass of 0.681 ? 0.031 M J and radius of 1.243 ? 0.072 R J yielding a mean density of 0.439 ? 0.069 g cm-3. By repeating our global fits with different parameter sets, we have performed a critical investigation of the fitting techniques used for previous Hungarian-made Automated Telescope planetary discoveries. We find that the system properties are robust against the choice of priors. The effects of fixed versus fitted limb darkening are also examined. HAT-P-24b probably maintains a small eccentricity of e = 0.052+0.022 --0.017, which is accepted over the circular orbit model with false alarm probability 5.8%. In the absence of eccentricity pumping, this result suggests that HAT-P-24b experiences less tidal dissipation than Jupiter. Due to relatively rapid stellar rotation, we estimate that HAT-P-24b should exhibit one of the largest known Rossiter-McLaughlin effect amplitudes for an exoplanet ( Delta *DV RM 95 m s--1) and thus a precise measurement of the sky-projected spin-orbit alignment should be possible.
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 Tc = ...2454715.02174 ? 0.00020 (BJD), and transit duration 0.1131 ? 0.0009 days. The host star has a mass of 0.77 ? 0.03 M , radius of 0.75 ? 0.04 R , effective temperature 4803 ? 80 K, and metallicity Fe/H = +0.10 ? 0.08. The planetary companion has a mass of 0.197 ? 0.013 M J and radius of 0.995 ? 0.052 R J, yielding a mean density of 0.25 ? 0.04 g 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 Tc = 2455091.53417 ? 0.00034 (BJD), and transit duration 0.1182 ? 0.0014 days. The host star has a mass of 0.84 ? 0.04 M , radius of 0.82 ? 0.05 R , effective temperature 4990 ? 130 K, and metallicity Fe/H = +0.23 ? 0.08. The planetary companion has a mass of 0.292 ? 0.018 M J and radius of 1.132 ? 0.072 R J, yielding a mean density of 0.25 ? 0.04 g 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. This calls into question the heretofore suggestive correlation between the inferred core mass and host star metallicity for Saturn-mass planets.
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