Eliminating the Coriols Effect in Liquid Mirrors

If uncorrected, the Coriolis force due to the rotation of the Earth causes significant aberration of images produced by large liquid-mirror telescopes. We show that this problem can be eliminated by a fixed compensating tilt of the liquid-mirror rotation axis. The required tilt angle, which is a function of latitude and mirror rotation rate, is of order 10 arcsec for current telescopes. This result removes the last fundamental obstacle to achieving diffraction-limited performance with large liquid mirrors.Comment: 8 pages 1 figure, submitted to PAS

Lunar orbital photogaphic planning charts for candidate Apollo J-missions

A technique is presented for minimizing Mapping Camera film usage by reducing redundant coverage while meeting the desired sidelap of greater than or equal to 55%. The technique uses the normal groundtrack separation determined as a function of the number of revolutions between the respective tracks, of the initial and final nodal azimuths (or orbital inclination), and of the lunar latitude. The technique is also applicable for planning Panoramic Camera photography such that photographic contiguity is attained but redundant coverage is minimized. Graphs are included for planning mapping camera (MC) and panoramic camera (PC) photographic passes for a specific mission (i.e., specific groundtracks) to Descartes (Apollo 16), for specific missions to potential Apollo 17 sites such as Alphonsus, Proclus, Gassendi, Davy, and Tycho, and for a potential Apollo orbit-only mission with a nodal azimuth of 85 deg. Graphs are also included for determining the maximum number of revolutions which can elapse between successive MC and PC passes, for greater than or equal 55% sidelap and rectified contiguity respectively, for nodal azimuths between 5 deg and 85 deg

Astronomical seeing and ground-layer turbulence in the Canadian High Arctic

We report results of a two-year campaign of measurements, during arctic winter darkness, of optical turbulence in the atmospheric boundary-layer above the Polar Environment Atmospheric Laboratory in northern Ellesmere Island (latitude +80 deg N). The data reveal that the ground-layer turbulence in the Arctic is often quite weak, even at the comparatively-low 610 m altitude of this site. The median and 25th percentile ground-layer seeing, at a height of 20 m, are found to be 0.57 and 0.25 arcsec, respectively. When combined with a free-atmosphere component of 0.30 arcsec, the median and 25th percentile total seeing for this height is 0.68 and 0.42 arcsec respectively. The median total seeing from a height of 7 m is estimated to be 0.81 arcsec. These values are comparable to those found at the best high-altitude astronomical sites

Factors Predicting Beta-Blocker Treatment after Myocardial Infarction in Patients with Type 2 Diabetes

OBJECTIVE – Beta-blockers remain important for secondary prevention after myocardial infarction (MI). Despite clinical guideline recommendations, the potential for poor glycemic control and masking warning signs of hypoglycemia limit their utilization in type 2 diabetes. This study evaluated factors predicting post-MI beta-blocker initiation among type 2 diabetic patients. RESEARCH DESIGN AND METHODS – A retrospective cohort of employed, commercially insured individuals was developed using de-identified enrollment files, medical claims, and pharmacy claims from 2007-2009 in the U.S. Inclusion criteria: (1) type 2 diabetes, (2) ≥18 years old, (3) continuous eligibility, (4) MI. Exclusion criteria: (1) females prescribed metformin exclusively without diabetes diagnosis, (2) \u3c6 months eligibility pre-MI, (3) MI before diabetes identified, (4) pre-MI beta-blocker, (5) receipt of sotalol post-MI, (6) no prescription claims, (7) \u3c30 days between discharge and study end. Multivariable logistic regression with manual backward elimination was used to evaluate predictors of beta-blocker initiation. RESULTS – Of 341 type 2 diabetic patients, only 167 (49.0%) initiated beta-blockers within 30 days of discharge. Patients on a calcium channel blocker (ORadj: 2.63) and patients taking 1 to 5 medications (ORadj: 3.59) were more likely to initiate beta-blockers post-MI. Patients with heart failure (ORadj: 0.45) or an arrhythmia (ORadj: 0.44) were less likely to initiate beta-blockers as well as patients with renal failure who are not taking a diuretic (ORadj: 0.17). CONCLUSIONS – Although these results might not apply to older populations, they support the need for further investigation to determine whether more patients with type 2 diabetes could benefit from beta-blocker treatment post-MI

NASAs Orbital Debris JAO/ES-MCAT Optical Telescope Facility on Ascension Island

The NASA Orbital Debris Program Office has a long-standing optical program begun over three and a half decades ago in 1984, designed to observe the Earth-orbiting environment with optical telescopes. Photometrically calibrated optical data provides a statistical sample for input to NASA models of the debris population for understanding the current and future debris environment around the Earth. Tracked objects and orbits allow for analysis of break-up events. Both known (correlated target in the SSN catalogue, or CT) and unknown (uncorrelated target, or UCT) objects are of interest to better understand how to protect current spacecraft and design more robust future operational satellites, and advise on how policies and practices can lead to protecting the environment itself for future generations. In 2015, a joint NASA JSC Air Force Research Labs (AFRL) project culminated in the installation of the 1.3-meter Eugene Stansbery Meter Class Autonomous Telescope, ES-MCAT (a.k.a. MCAT) on Ascension Island. This DFM Engineering designed telescope provides nearly five-times greater light-collecting power than its predecessor, the 0.6-m MODEST telescope, and faster tracking capabilities by both the telescope and the 7-m ObservaDome. This allows for all orbital regimes to be easily within reach, ranging from low Earth to geosynchronous orbits. Extensive testing and commissioning activities of this custom system led to successfully reaching Initial Operational Capability in 2018, and the facility is currently on track to reach Full Operational Capability. The John Africano Observatory (JAO) comprises the primary 1.3-m ES-MCAT facility, the adjacent tower platform with a 0.4-m telescope, a sophisticated suite of weather instruments, and custom software by Euclid Research for autonomously running the entire system, including monitoring the weather and hardware, tasking all components, and collecting, processing, and analyzing the data. The mission of JAO and MCAT will be discussed, including survey and tracking tasking, a full discussion of data calibration, and both optics and weather-dependent performance

Lunar surface temperatures from Apollo 11 data

Thermal analysis of lunar surface temperature data from Apollo 11 fligh