... In order to obtain a quantitative estimate of the accuracy and reliability of our data reduction procedures and results, we have performed a data reduction pipeline based on the following steps: i) define a set of simulated HST-like images with synthetic globular cluster stellar distributions, which provide the ``true'' data for comparison; ii) convolve these images with appropriate assumptions of PSF and noise in order to construct simulated `` observed '' ... It contains 470 stars. b) ...

... The J, H and K bands are characterized by a bright background, such a background is mainly due to the emission of atmospheric lines and of thermal radiation. ... If the source cover a large fraction of the slit, spectra off-source must be observed to adequately sample the sky background. ... The on chip integration time (time spent in each position of the slit) must not exceed 40 seconds in J and H bands and 60 seconds in K band. ... We suggest a sequence of 10 for each elementary integration time. ...

... The new emission line galaxies are listed in Table 2 containing the following information: . column 1: The object's IAU-type name with the prefix HS. ... This was not corrected in the figure shown in Appendix A. HS1214+3801 : This is seemingly a supergiant H II -region at the very rim of the nearby edge-on disc galaxy (SA(s)cd) NGC 4244 (V hel = 224 kms -1 and B T =10.88). ... To check this option one needs a detailed map of the NGC 4244 velocity field including HS 1214+3801. ...

... This thread contains a step-by-step recipe to extract MOS spectra of a point-like source observed in Imaging mode and to create associated response matrices, starting from a calibrated, concatenated event list (either produced with emproc or available as PPS product; here it has the assumed file name MOS.fits ). ... The users should note that the SAS metatask xmmselect allows them to interactively define source and background regions (via ds9) and to run backscale on the fly. ...

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) . ...

... all new HIPASS galaxies (Table 2.4) that have no yet been observed with the ATCA . ... Table : Remaining ATCA target list (sorted by RA) -------------------------------------------------------------------------------- Name RA DEC ID Max mom0 mom1 mom2 w50 w20 -------------------------------------------------------------------------------- ZSS 13 07:33:16 -28:41:07 new -HIZSS013 0.151 9.2 2077.6 21.6 52.8 144.6 HIP 358 07:44:56 -41:47:02 ESO311-G006/7 0.262 30.9 1049.4 34.5 127.1 149.5 ...

Once students get the hang of it, they can find and measure the brightness of Delta Cephei in a few minutes. ... of Delta Cephei . ... Oct. ... The following table lists the measurements of Delta Cephei made by one amateur astronomer in autumn 1990. ... 4.0 . ... This activity is a simplified version of one that appeared in Hands-On Astrophysics, a series of activities prepared by the American Association of Variable Star Observers with support from the National Science Foundation. << previous page | ...

... Galaxies 99 Cosmic background with model of cloudy interstellar medium Yu. ... Figure 1: Averaged spectrum of the cosmic background I f in frequency range 0.25 200 MHz for the Galactic poles. ... First interpretation of the cosmic noise background spectrum at broad band frequency range 0.25 200 MHz with a model of the cloudy interstellar medium ISM is presented here. ... Synthesized background spectra I f for regions of the Galactic poles at the frequency range 0.25 200 MHz is presented in Fig. ...

... Team . ... GRB mini-workshop 2006 . ... On April 8, 2005, an optical afterglow of the GRB 050408 was discovered with the SAO's telescopes (the 1-meter telescope Zeiss and 6-meter telescope BTA) within the framework of a joint BTA request (SAO RAS + IAA CSIC, Granada, Spain) on optical identification of gamma-ray bursts. We first detected a variable object only by our own data in the localization error-box reported by the space observatory HETE and then it was confirmed by our observations in SAO. ...

... The Search of a pulsar Once the dedispersed time series is obtained, a Fourier transformation is performed. ... 2 Binary parameters The orbit of a pulsar , as well as any object, in a binary system is determined in its geometrical characteristics, space displacement and syncronised in time by the following parameters : Semimajor axis Eccentricity Longitude of periastron Binary period Time of ascending node a e PB T0 True spin period and observed spin period The ...

... Tonight's Sky . ... The Magazine . ... Observing . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Bright planets meet at dusk . ... Astronomy magazine subscribers can read the full article for free. ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter....

Follow-up astrometry and recoveries are made with the ANU 40 inch (1.0-m) f/8 reflector at Siding Spring Observatory (IAU code 413). ... A routine follow-up of 2003 WY153 on 2003 Dec 15 became much more than routine when a faint object with unusual motion vector was found close to the target asteroid. ... During routine astrometry with the 1.0-m to improve the orbit of the Apollo asteroid 2004 CB, the asteroid was found on March 30 to have a short tail! ... Siding Spring Survey Main Page . ...

... A detailed study of two consecutive bright points observed simultaneously with CDS, EIT and MDI is presented. The analysis of the evolution of the photospheric magnetic features and their coronal counterpart shows that there is a linear dependence between the EIT Fe XII 195? flux and the total magnetic flux of the photospheric bipolarity. ... In a follow-up study, we used wide slit (90arcsec240arcsec) movies of four EIT coronal bright points (BPs) obtained with CDS. ...

... The Galactic low-mass X-ray binary GS 2023+338 was discovered during the burst on May 22, 1989 with the Japanise satellite Ginga (aka Galaxy). The flux reached 17 crabs (this unit of flux measurement is an bright X-ray source, Crab Nebula) at 10-35 keV. ... No other radio telescope worldwide carried out multi-frequency measurements. ... Upon 14 days the radio flux fell below the detection level at the RATAN-600 in relation to the decrease of the X-ray flux. ...

... The performance of each algorithm on the simulated lightcurves is scored accor ding to the rates of false positive (Type I) and false negative (Type II) errors. ... Combined: threshold normalization = 5 в 10 -4 References · Aschwanden, M.J., Nightingale, R.W. Tarball, T.D., & Wolfson, C.J. 2000, Ap J , 5 3 5 , 1 0 2 7 · Hudson, H.S. 1991, SoPh, 133, 357 Figure 3 Calibrating the event detection algorithms to optimize false positives, using the simulated lightcurves with zero events. ...

Appendix C Radiative Transfer for a Two-Level System This appendix details how to derive the total column density of a linear rigid-rotor molecule, such as CO, from the observed brightness of its rotational transition. ... C.2 Radiative Transfer for a Two-Level System I now consider emission in a two-level system from an upper J + 1 (denoted `u') to lower J (denoted `l') state. ... Spontaneous emission is controlled by the A coefficient, with a rate Aul nu . ... Tex exp(-31. ...

... Spherical aberration, coma, and astigmatism are also easily observed using the star test. ... Off-axis images are complex. ... Fig. ... Diffraction by a circular aperture as a function of defocus for no aberration Airy Disk 1 wave defocus Less than 1 wave defocus Fig. ... Diffraction by a circular aperture as a function of defocus for third-order spherical aberration Paraxial Focus Small distance inside paraxial focus Moderate distance from marginal focus Immediate neighborhood of marginal focus Fig...

... The package AMPLE (Adaptable Minor Planet Ephemerides) is dedicated to solving a number of problems concerning minor planets with the aid of IBM-type personal computer. ... Obtaining selection of orbital elements and/ or photometric parameters of minor planets in conformity with imposed restrictions. ... The orbital elements of all minor planets used in AMPLE for 2015 have been determined in IAA on the ground of available observations in the catalogue of observations of the Minor Planet Center. ...

This page is devoted to information on Supernova 1998dh in NGC 7541 . ... Information on the original web pages for many of these images can be found on the Supernova links web page. ... Perpignan Observatory 1998dh page in French [ Translate ] . ... LOSS image sequence (color) marked images NEW 4/6/99 . click on image for more color images) This is a color composite image of Supernova 1998dh in NGC 7541 . ... Perpignan Observatory images 7/30/98 00h25m31s . ... Pedro RИ image 8/21/98 . ...

... The following charts/text are intended as tools for monitoring the Type Ia supernovae ( SNe ) event visually or photographically (utilizing telescope equipped CCD equipment).The files include: A replication of The Type Ia SNe , V- magnitude (with data point checks from other cited references)and color index (B-V) templete (to indicate a general color-related trend of the type Ia ... I believe this might help alleviate some of the problems involving the making of acceptable amateur light curves...