Observatory [Lake Angelus]

Observatory is near Lake Angelus, Mich. (five miles north of Pontiac). 24" reflecting telescope began operations in July 1930; also included a 10 1/2" reflector. Established and deeded to the university by Robert R. McMath, Francis McMath, and Judge Henry S. Hulbert. An additional 50' tower telescope was added in 1935/ 1946 and 70' tower telescope and office building added in 1940. On verso: Kodatone; Nov - 7 1935; Eastman Kodak Stores; Detroit

Observatory [Lake Angelus]

Observatory is near Lake Angelus, Mich. (five miles north of Pontiac). 24" reflecting telescope began operations in July 1930; also included a 10 1/2" reflector. Established and deeded to the university by Robert R. McMath, Francis McMath, and Judge Henry S. Hulbert. An additional 50' tower telescope was added in 1935/ 1946 and 70' tower telescope and office building added in 1940. Several people in image. On verso: Kodatone; Nov - 7 1935; Eastman Kodak Stores; Detroit

Observatory [Lake Angelus]

Observatory is near Lake Angelus, Mich. (five miles north of Pontiac). 24" reflecting telescope began operations in July 1930; also included a 10 1/2" reflector. Established and deeded to the university by Robert R. McMath, Francis McMath, and Judge Henry S. Hulbert. An additional 50' tower telescope was added in 1935/ 1946 and 70' tower telescope and office building added in 1940. On verso: Kodatone; May 16, 1936; Eastman Kodak Stores; Detroit

McMath-Hulbert Observatory

Observatory is near Lake Angelus, Mich. (five miles north of Pontiac). 24" reflecting telescope began operations in July 1930; also included a 10 1/2" reflector. Established and deeded to the university by Robert R. McMath, Francis McMath, and Judge Henry S. Hulbert. An additional 50' tower telescope was added in 1935/ 1946 and 70' tower telescope and office building added in 1940.

McMath-Hulbert Observatory

Observatory is near Lake Angelus, Mich. (five miles north of Pontiac). 24" reflecting telescope began operations in July 1930; also included a 10 1/2" reflector. Established and deeded to the university by Robert R. McMath, Francis McMath, and Judge Henry S. Hulbert. An additional 50' tower telescope was added in 1935/ 1946 and 70' tower telescope and office building added in 1940.

McMath-Hulbert Observatory [Lake Angelus, MI]

Observatory is near Lake Angelus, Mich. (five miles north of Pontiac). 24" reflecting telescope began operations in July 1930; also included a 10 1/2" reflector. Established and deeded to the university by Robert R. McMath, Francis McMath, and Judge Henry S. Hulbert. An additional 50' tower telescope was added in 1935/ 1946 and 70' tower telescope and office building added in 1940. Image is photograph of a painting.

Sky with ocean joined : proceedings of the sesquicentennial symposia of the U.S. Naval Observatory, December 5 and 8, 1980 /

Mode of access: Internet.

WASP-41b: A Transiting Hot Jupiter Planet Orbiting a Magnetically Active G8V Star

We report the discovery of a transiting planet with an orbital period of 3.05 days orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8 V star (V=11.6) with a metallicity close to solar ([Fe/H]=-0.08±0.09). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the Ca ii H and K ines and photometric variability with a period of 18.4 days and an amplitude of about 1%. We use a new method to show quantitatively that this periodic signal has a low false-alarm probability. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8 Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.92±0.06 M, 1.20±0.06 R). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and the level of chromospheric activity in their host stars.

Qatar-1b: a hot Jupiter orbiting a metal-rich K dwarf star

We report the discovery and initial characterization of Qatar-1b, a hot Jupiter-orbiting metal-rich K dwarf star, the first planet discovered by the Qatar Exoplanet Survey. We describe the strategy used to select candidate transiting planets from photometry generated by the Qatar Exoplanet Survey camera array. We examine the rate of astrophysical and other false positives found during the spectroscopic reconnaissance of the initial batch of candidates. A simultaneous fit to the follow-up radial velocities and photometry of Qatar-1b yields a planetary mass of 1.09 ± 0.08 MJ and a radius of 1.16 ± 0.05 RJ. The orbital period and separation are 1.420 033 ± 0.000 016 d and 0.023 43 ± 0.000 26 au for an orbit assumed to be circular. The stellar density, effective temperature and rotation rate indicate an age greater than 4 Gyr for the system.

Finding exoplanets orbiting young active stars - I. Technique

Stellar activity, such as starspots, can induce radial velocity (RV) variations that can mask or even mimic the RV signature of orbiting exoplanets. For this reason RV exoplanet surveys have been unsuccessful when searching for planets around young, active stars and are therefore failing to explore an important regime which can help to reveal how planets form and migrate. This paper describes a new technique to remove spot signatures from the stellar line-profiles of moderately rotating, active stars (v sin i ranging from 10 to 50 km s(-1)). By doing so it allows planetary RV signals to be uncovered. We used simulated models of a G5V type star with differing dark spots on its surface along with archive data of the known active star HD 49933 to validate our method. The results showed that starspots could be effectively cleaned from the line-profiles so that the stellar RV jitter was reduced by more than 80 per cent. Applying this procedure to the same models and HD 49933 data, but with fake planets injected, enabled the effective removal of starspots so that Jupiter mass planets on short orbital periods were successfully recovered. These results show that this approach can be useful in the search for hot-Jupiter planets that orbit around young, active stars with a v sin i of similar to 10-50 km/s.

SALSA: a tool to estimate the stray light contamination for low-Earth orbit observatories

Stray light contamination reduces considerably the precision of photometric of faint stars for low altitude spaceborne observatories. When measuring faint objects, the necessity of coping with stray light contamination arises in order to avoid systematic impacts on low signal-to-noise images. Stray light contamination can be represented by a flat offset in CCD data. Mitigation techniques begin by a comprehensive study during the design phase, followed by the use of target pointing optimisation and post-processing methods. We present a code that aims at simulating the stray-light contamination in low-Earth orbit coming from reflexion of solar light by the Earth. StrAy Light SimulAtor (SALSA) is a tool intended to be used at an early stage as a tool to evaluate the effective visible region in the sky and, therefore to optimise the observation sequence. SALSA can compute Earth stray light contamination for significant periods of time allowing missionwide parameters to be optimised (e.g. impose constraints on the point source transmission function (PST) and/or on the altitude of the satellite). It can also be used to study the behaviour of the stray light at different seasons or latitudes. Given the position of the satellite with respect to the Earth and the Sun, SALSA computes the stray light at the entrance of the telescope following a geometrical technique. After characterising the illuminated region of the Earth, the portion of illuminated Earth that affects the satellite is calculated. Then, the flux of reflected solar photons is evaluated at the entrance of the telescope. Using the PST of the instrument, the final stray light contamination at the detector is calculated. The analysis tools include time series analysis of the contamination, evaluation of the sky coverage and an objects visibility predictor. Effects of the South Atlantic Anomaly and of any shutdown periods of the instrument can be added. Several designs or mission concepts can be easily tested and compared. The code is not thought as a stand-alone mission designer. Its mandatory inputs are a time series describing the trajectory of the satellite and the characteristics of the instrument. This software suite has been applied to the design and analysis of CHEOPS (CHaracterizing ExOPlanet Satellite). This mission requires very high precision photometry to detect very shallow transits of exoplanets. Different altitudes and characteristics of the detector have been studied in order to find the best parameters, that reduce the effect of contamination. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Astronomical observations made at the Observatory of Cambridge.

Mode of access: Internet.

Technology for Scanning Astronomical Photographic Plates

ACM Computing Classification System (1998): J.2.

Blast atlas: a virtual observatory for genomes

Following the completion of the draft Human Genome in 2001, genomic sequence data is becoming available at an accelerating rate, fueled by advances in sequencing and computational technology. Meanwhile, large collections of astronomical and geospatial data have allowed the creation of virtual observatories, accessible throughout the world and requiring only commodity hardware. Through a combination of advances in data management, data mining and visualization, this infrastructure enables the development of new scientific and educational applications as diverse as galaxy classification and real-time tracking of earthquakes and volcanic plumes. In the present paper, we describe steps taken along a similar path towards a virtual observatory for genomes – an immersive three-dimensional visual navigation and query system for comparative genomic data.

Approximate Bayesian Computation for astronomical model analysis : a case study in galaxy demographics and morphological transformation at high redshift

Approximate Bayesian Computation’ (ABC) represents a powerful methodology for the analysis of complex stochastic systems for which the likelihood of the observed data under an arbitrary set of input parameters may be entirely intractable – the latter condition rendering useless the standard machinery of tractable likelihood-based, Bayesian statistical inference [e.g. conventional Markov chain Monte Carlo (MCMC) simulation]. In this paper, we demonstrate the potential of ABC for astronomical model analysis by application to a case study in the morphological transformation of high-redshift galaxies. To this end, we develop, first, a stochastic model for the competing processes of merging and secular evolution in the early Universe, and secondly, through an ABC-based comparison against the observed demographics of massive (Mgal > 1011 M⊙) galaxies (at 1.5 < z < 3) in the Cosmic Assembly Near-IR Deep Extragalatic Legacy Survey (CANDELS)/Extended Groth Strip (EGS) data set we derive posterior probability densities for the key parameters of this model. The ‘Sequential Monte Carlo’ implementation of ABC exhibited herein, featuring both a self-generating target sequence and self-refining MCMC kernel, is amongst the most efficient of contemporary approaches to this important statistical algorithm. We highlight as well through our chosen case study the value of careful summary statistic selection, and demonstrate two modern strategies for assessment and optimization in this regard. Ultimately, our ABC analysis of the high-redshift morphological mix returns tight constraints on the evolving merger rate in the early Universe and favours major merging (with disc survival or rapid reformation) over secular evolution as the mechanism most responsible for building up the first generation of bulges in early-type discs.