... The concerns here are similar to those for observing bright targets; saturation and blooming of the bright companion PSF must not impact the faint target. Also, one may need to consider subtracting the PSF of the bright object, and effects which limit the accuracy of that subtraction. If the bright companion will saturate and bloom, it will be necessary to rotate the CCD so that blooming along the CCD columns does not obliterate the faint target. ...

In the PROJECT we are using the following peculiar . features of RATAN-600 . ... Brightness temperature sensitivity being equal to the antenna temperature sensitivity .. ... Receiver system .. ... Using aperture averaging effect. dual- beam and dual (multi-) frequency filtration, we demonstrated full filtration of the atmosphere noise down to the receiver noise at all scales of acoustics peaks ( Fig.1 , Fig 2 ). ... We select this frequency as the central one in our project. ... Antenna surface . ...

The CHIANTI database consists of 4 primary ASCII files for each ion in the database. contains the energy levels in cm^(-1) It includes both experimental data and theoretical values of the levels energies. References: %Observed energy levels (2): Feldman, U., Curdt, W., Landi, E., Wilhelm, K., 2000, ApJ, 544, 508 %Observed energy levels (3,4,5): Sandlin, G.D., Bruekner, G.E., Scherrer, V.E., Tousey, R., 1976, ApJ, 205, L47 %Observed energy levels (6 to 15): Fuhr, J.R., et al., ...

... Science User Portal . ... ESO, the European Southern Observatory . ... Travel and Contacts . Travel to ESO Headquarters . ... Travel to E-ELT Armazones . ... Survey Telescopes . ... Star Clusters . ... Stars@ESO . ... ESO Science Newsletter . ... ESO 3.6-metre telescope . ... MPG/ESO 2.2-metre telescope . ... ESO 1-metre Schmidt telescope . ... ESO Science Outreach Network . ... This chart shows the brightness variation ("light-curve") of the star OGLE-TR-3 obtained during the OGLE observations. ...

The Cosmic Microwave Background Radiation Temperature Work in groups of 2-4. ... Due 1999 April 15 In this laboratory exercise, you will use the radio telescope on the roof of Science B to measure the intensity of the Cosmic Microwave Background Radiation (CMBR). ... The output of the telescope when pointing at the sky will then be 2 Tsys = Trec + Tsky : The temperature of the sky can in principle arise from two sources, radiation from the atmosphere and radiation from outer space (the CMBR). ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

... 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 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...

... One characteristic of the ATCA dishes is that they are big by 3-mm standards. Indeed van Hoerner (1967) has considered the limits to the size of an antenna before various effects become significant. ... As the ATCA dishes are twice this, it is not surprise that the ATCA antenna gain and primary beam response varies as a result of thermal distortions. ... A gain/elevation correction will solve this - to first order at least. ... This might be an important effect for widefield imaging and mosaicing. ...

... Zodiacal Light and the False Dawn . ... An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once considered a false dawn, this triangle of light is actually Zodiacal Light, light reflected from interplanetary dust particles. APOD: 2004 August 24- Supply Ship Approaches the Space Station . ... Looking Out Over Mars . ... Earth at Night . ... Lightning on Earth . ... August . ...

... Actual stars are expected to be more complicated than these simulations. ... The spot may be entirely visible most of the time (one would observe a prolonged flux minimum low), and then part of it may disappear over the horizon briefly and then return (slow rise and then fall back to constant level). ... With the set of observations taken here, I have information available from several comparison stars and color information. ... The period found must be consistent with the data from any given night....

... They are concerned with Attitude Control System of the spacecraft, satellite visibility from tracking stations, limits on the satellite autonomous operations during the orbit, and needs for auxiliary operations with the spacecraft. ... Among the operational constraints the most important one is the number of programmed slews per orbit, which determines the maximum number of radio sources to be observed during one orbit. ... System temperature (K) . ... Progress of the RadioAstron Project in Pictures...

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 | ...

... Armagh Observatory received many telephone and internet reports from members of the public regarding sightings of a bright meteor or fireball which crossed over Northern Ireland in the early morning of Sunday, 10th October. ... Account: I was driving on the main Armagh/Portadown Road travelling towards Richhill when the sky in front of me was lit up by a couple of very bright flashes of light which were followed by a trail of white light. ... The trail faded over approximately 20 seconds. ...

... 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....

RADIOASTROPHYSICAL DEPARTMENT • INSTITUTE OF SOLAR-TERRESTRIAL PHYSICS RAS SB . ... SSRT - Possibilities of observing . ... Investigations of the SSRT 5.7 GHz radio maps in conjunction with images obtained in other emission ranges, suggested the following conclsions: . ... Solar images obtained in line H a ;(on the left, 16:11 UT, Big Bear observatory) and in the microwave emission (on the right, 04:04 UT, SSRT) 4 march 1997 . ...

... The bright supernova (hereafter SN) in the galaxy NGC 4527 was first sighted by S. Knight (USA) on April 13.17UT at magnitude ~14.0v. The report of the sighting was subsequently forwarded by phone to the AAVSO. ... SN 1991T. The galaxy NGC 4527 is an Sb(s)II type galaxy with an apparent Blue magnitude of 11.32 (Shapley-Ames, 1981). ... An analysis of this event utilizing visual observations by amateurs, plus a light curve is presented.. ... THE LIGHT CURVE: . ... ISN SN 1991T web page . ...

... The MMT optical spectra of SBS 0335-052W were obtained on 1996 January 19 with the Red Channel of the MMT Spectrograph. ... The linear scale is 1 = 263 pc at the distance to SBS 0335-052W of 54.1 Mpc. ... In Table 1, the observed line intensities and intensities corrected for interstellar extinction for SBS 0335-052W are shown along with extinction coefficient C (H ), observed flux of the H emission line, the equivalent width EW (H ) and equivalent width of absorption Balmer hydrogen lines EW (abs)....

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. ...

... Fitting the observed dependence includes calculations of the polarization cross-sections averaged over particles orientation and size distribution, their normalization and the comparison of obtained dependencies with Serkowski's curve representing observational data for a chosen star. ... Variations of the polarization factors with wavelength are shown in Fig. 16 for homogeneous spheroidal particles with PF orientation. ... The distinction between prolate and oblate spheroids is also clearly seen. ...