... Information about a variety of different calendars for different cultures (e.g., Christian, Jewish, Muslim, Chinese, Hindu etc.) ... In addition, the Chinese had two different ways of interpreting and observing celestial events. One way the Chinese used astronomy was known as lifa; it was a discipline that aimed to understand the regularities and the predictable events in the celestial system through careful, observations, measurements and records. ... back to Teachers' Newsletter Main Page ...

Observatory Support . ... The science header keyword ORIENTAT is populated by adding the angle between the HST V3 axis and the detector Y axis to what we will call the "commanded roll" (North to V3 through East). The V3-detY angles that were relevant at a given observation's epoch are given as a header keyword (beta_2) in the Observation Log files (aka jitter files). ... The commanded roll and the jitter file's ROLL_AVG should agree to within 0.05 degrees, usually better than 0.02deg. ...

For solar wind dials without any explanatory text, see this page . ... There are three logs, one for each condition index ( K P , Solar Wind ,and NOAA/SEC .) ... More about the solar wind's recent behavior can be found on my Current Solar Wind Conditions page. ... Other items of interest include NOAA/SEC Current Conditions , my composite current Auroral Images page, Windows on the Universe: Space Weather , and Public Outreach Index, Department of Space Physics and Astronomy, Rice University . ...

... Team . ... The main goal of observations of GRB host galaxies is accumulation of statistics of their spectroscopic and photometric properties. ... The Hubble diagram for 22 GRB host galaxies with known magnitudes and redshifts (GRB 970228, GRB 970508, GRB 970828, GRB 971214, GRB 980613, GRB 980703, GRB 990123, GRB 990510, GRB 990712, GRB 9912008, GRB 991216, GRB 000131, GRB 000210, GRB 000301C, GRB 000418, GRB 000911, GRB 000926, GRB 001109, GRB 010222, GRB 010921, GRB 011121 and GRB011211). ... 600...

... Research . ... The major problem in HVC research is the unknown distance towards most of the HVCs. ... Thilker et al. (2004) used the Green Bank Telescope (GBT) to map an area of $7^{\circ} \times 7^{\circ}$ around M31 in H i . They discovered a population of HVCs located within a projected distance of about $50~\mathrm{kpc}$ from M31. ... 2004). ... The remaining HVCs around M31 are isolated in position and velocity and may represent primordial, dark-matter-dominated clouds. ...

... They were determined as a result of orbit improving on the base of all kinds of optical observations available in the catalog of observations of the Minor Planet Center on March 16, 2014 (radar observations have not been used at this stage). ... As the MPC orbits do not all were improved simultaneously with EMP orbits, only 383866 sets of elements were used for data comparison (for selected sets of elements process of improvement had started with the use of the same observations). ...

Next: Reducing the observations Up: PEPSYS general photometry Previous: Influencing the plan . ... If the telescope and instrumentation are unfamiliar to you, you may have trouble keeping to the schedule for the first night or two, so try to work with a previous observer on the equipment for a night or two of training before your observing run. If you fall behind, try to keep as many low-altitude observations of extinction stars as you can, and drop some circumzenithal ones if necessary. ...

... The most precisely determined characteristic for accreting neutron stars (NS's) is their period. ... Period changes show fluctuations. ... Some applications of stochastic processes in astrophysics especially in accreting systems were discussed in Lipunov (1987),Hoshino Takeshima (1993) and Lipunov (1992).In Hoshino Takeshima (1993) the authors, using simple models of MHD turbulence, try to explain aperiodic changes in X-ray luminosity of X-ray pulsars. ... Here, -constant angular momentum. ...

From Herschel's catalog, the first accurate stellar parallax measurement of 0.32 seconds of arc for the star 61 Cygni was published by the F.W. Bessel in 1838. ... This distance is equivalent to 3.26 light years. ... The Universe was now a large place and the intrinsic energy output of the stars had to be huge in order that their light could reach us. ... An Orbit in Curved Space This is a prediction made by General Relativity and confirmed by direct observation of Mercury. ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

The database contains references to the papers, data files and links to the Internet resources related to measurements and calculations of the optical constants in the wavelength interval from X-rays to radio domain. ... References to some useful books and reviews on the subject (e.g. the classical handbooks edited by E.D.Palik) and links to Internet collections of optical constants and personal WWW pages with related software were also placed in the database. You have arrived at our welcome page. ...

These observations are aimed at fully charactering FORS1 photometric system (UBVRI zero-points, color-terms and extinction coefficients) for the Tektronix 2048x2048 pixel CCD (24µm px) . To this aim, the two Landolt/Stetson photometric fields SA95 and SA101 will be observed on a number of epochs and at different airmasses during February and March 2007. ... SA101 . ... OBs for SA101 have to be observed during evenigh twilight (exceptions are expected for the second half of March) . ...

RTT150 . ... This search system is designed for generating the necessary information on series of pointings (observations of each source consist of sets of exposures with different filters and sometimes with different exposure times) for observed sources. Search results appear at the separate page as a table with the following data: . DATE - real (not evening!) observations date (in YYYY-MM-DD format); . ... Bin - minimal CCD binning mode (may vary during the observations); . ...

... Analysis of in-orbit data closely follow the CSL data analysis. Stars with known astrometric positions are matched with their image centroids. ... The measured position, the expected position and the offset between the measured and expected positions are calculated and written into a file. ... select catalogued positions for different observations/pointings (e.g. positions of objects in photometric sequence) . ... The new distortion map was generated from in-flight observations of the G153 field. ...

The following files list line and continuum emissivities from the Arcetri Spectral Code. ... Ne = 10^8 g-zipped file (phot cm^3 s^-1); Ne = 10^8 g-zipped file (erg cm^3 s-1) . ... File format (html): File format for the continuum files . ... File format (html): File format for binned line emission files The following files list transitions whose emissivities have values greater than a fixed amount (10^-19 phot s^-1 cm^+3 and 10^-30 erg s^-1 cm^+3 respectively): . ...

... The HST uses an onboard model of its orbit to perform in real-time various control functions relating to spacecraft operations and observation support. ... New coefficients for the ephemeris are updated every other day, and are archived as FITS keywords for each HST observation data set. Using these coefficients,an observer can perform a variety of calibration and characterization calculations relating to the orbital position and velocity of the telescope. ...

... All the parameters provided in this database have been obtained using the the MIRIAD ( Sault et al. 1995 ) task MBSPECT . MBSPECT makes a spectrum of the velocity (or frequency) axis of a cube. The spectrum is beam-weighted, over the width specified, for the other image axes. ... Robust parameters are calculated by using an algorithm which minimises the mean absolute deviation of the flux-weighted velocities. mask= This specifies the x-axis ranges to be excluded from any continuum fit. ...

... Archives . ... If you do not mind the time predictor, it is hard to believe that this is a light curve, time dependent data. ... It?s hard to say this data set is designed for time series analysis apart from the complication in statistical inference due to measurement errors. How to design the statistical study with measurement errors, huge gaps in time, and unequal time intervals is complex and unexplored. ... The following is R output without measurement errors. ... Chandra Blog . ...

Astronomy Discussion Forums . Forums: . ... Discussion Forums . ... Follow Up . Forum List | Follow Ups | Post Message | ... Login to Post . ... www.astronomy.net . About Astronomy Net | Advertise on Astronomy Net | ... Unless otherwise specified, web site content Copyright 1994-2016 John Huggins All Rights Reserved . Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... The experience of determination of the link between radio sources and dynamical reference frames is presented. To obtain this connection we used a series of very long baseline interferometry (VLBI) observations of the spacecraft Phobos-2 and angularly nearby quasars. ... The dynamical reference frame is determined by equator and equinox of these ephemerides. ... References . ... The relative orientation of the radio and dynamical reference frames can be described by a sequence of three rotations . ...