HAT-P-9b: A Low Density Planet Transiting a Moderately Faint F star

We report the discovery of a planet transiting a moderately faint (V=12.3 mag) late F star, with an orbital period of 3.92289 +/- 0.00004 days. From the transit light curve and radial velocity measurements we determine that the radius of the planet is R_p = 1.40 +/- 0.06 R_Jup and that the mass is M_p = 0.78 +/- 0.09 M_Jup. The density of the new planet, rho = 0.35 +/- 0.06 g cm^{-3}, fits to the low-density tail of the currently known transiting planets. We find that the center of transit is at T_c = 2454417.9077 +/- 0.0003 (HJD), and the total transit duration is 0.143 +/- 0.004 days. The host star has M_s = 1.28 +/- 0.13 M_Sun and R_s = 1.32 +/- 0.07 R_Sun.Comment: Submitted to ApJ; V2: Replaced with accepted versio

Enabling real-time multi-messenger astrophysics discoveries with deep learning

Multi-messenger astrophysics is a fast-growing, interdisciplinary field that combines data, which vary in volume and speed of data processing, from many different instruments that probe the Universe using different cosmic messengers: electromagnetic waves, cosmic rays, gravitational waves and neutrinos. In this Expert Recommendation, we review the key challenges of real-time observations of gravitational wave sources and their electromagnetic and astroparticle counterparts, and make a number of recommendations to maximize their potential for scientific discovery. These recommendations refer to the design of scalable and computationally efficient machine learning algorithms; the cyber-infrastructure to numerically simulate astrophysical sources, and to process and interpret multi-messenger astrophysics data; the management of gravitational wave detections to trigger real-time alerts for electromagnetic and astroparticle follow-ups; a vision to harness future developments of machine learning and cyber-infrastructure resources to cope with the big-data requirements; and the need to build a community of experts to realize the goals of multi-messenger astrophysics

CfA4: Light Curves for 94 Type Ia Supernovae

We present multi-band optical photometry of 94 spectroscopically-confirmed Type Ia supernovae (SN Ia) in the redshift range 0.0055 to 0.073, obtained between 2006 and 2011. There are a total of 5522 light curve points. We show that our natural system SN photometry has a precision of roughly 0.03 mag or better in BVr'i', 0.06 mag in u', and 0.07 mag in U for points brighter than 17.5 mag and estimate that it has a systematic uncertainty of 0.014, 0.010, 0.012, 0.014, 0.046, and 0.073 mag in BVr'i'u'U, respectively. Comparisons of our standard system photometry with published SN Ia light curves and comparison stars reveal mean agreement across samples in the range of ~0.00-0.03 mag. We discuss the recent measurements of our telescope-plus-detector throughput by direct monochromatic illumination by Cramer et al (in prep.). This technique measures the whole optical path through the telescope, auxiliary optics, filters, and detector under the same conditions used to make SN measurements. Extremely well-characterized natural-system passbands (both in wavelength and over time) are crucial for the next generation of SN Ia photometry to reach the 0.01 mag accuracy level. The current sample of low-z SN Ia is now sufficiently large to remove most of the statistical sampling error from the dark energy error budget. But pursuing the dark-energy systematic errors by determining highly-accurate detector passbands, combining optical and near-infrared (NIR) photometry and spectra, using the nearby sample to illuminate the population properties of SN Ia, and measuring the local departures from the Hubble flow will benefit from larger, carefully measured nearby samples.Comment: 43 page

Google Summer of Code with OpenAstronomy

<p>In the lightning talk I summarized the OpenAstronomy involvement in the Google Summer of Code mentorship program.</p

Astroquery: querying astronomical web forms and databases

<p>Astroquery is an Astropy affiliated package for a set of tools for querying astronomical web forms and databases. In this lightning talk I give an overview of the available services and the usage of the package including a live demo of a typical use case.</p

Rotation periods for very low mass stars in Praesepe

The definitive version can be found at: http://onlinelibrary.wiley.com/ Copyright Royal Astronomical SocietyWe investigate the rotation periods of fully convective very low mass (VLM, M 0.6 M-circle dot in this cluster which have periods of 7-14 d. Thus, we confirm that the period-mass distribution in Praesepe exhibits a radical break at M similar to 0.3-0.6 M-circle dot. Our data indicate a positive period-mass trend in the VLM regime, similar to younger clusters. In addition, the scatter of the periods increases with mass. For the M > 0.3 M-circle dot objects in our sample, the period distribution is probably affected by binarity. By comparing the Praesepe periods with literature samples in the cluster NGC 2516 (age similar to 150 Myr) we constrain the spin-down in the VLM regime. An exponential rotational braking law P proportional to exp (t/tau) with a mass-dependent tau is required to reproduce the data. The spin-down time-scale tau increases steeply towards lower masses; we derive tau similar to 0.5 Gyr for 0.3 M-circle dot and > 1 Gyr for 0.1 M-circle dot. These constraints are consistent with the current paradigm of the spin-down due to wind braking. We discuss possible physical origins of this behaviour and prospects for future work.Peer reviewe

Chandra-MARX/marxs: V1.0

This is the first production ready release of the MARXS package