Next: Infrared Data Up: Contents Previous: Optical Photometry . ... For example, one method is to derive the spectral energy distribution (SED) for a target star and compare it to the SED of a dereddened standard star. ... Temperature can be determine via the B - V color (Gilliland 1985): . ... The results produced small extinctions to the background stars of between A and A . ... The most accurate extinction calculation requires both IR and spectral data. Infrared Data . Spectroscopic Data . ...

23may12: strobe lights from yiye avila's tower on mount roncador . ... On 21may12 I made a video of yiye avila's tower starting around 18:30. ... canon sx230hs camera . ... There are two strobes, one 1/2 way up tower (just below the donut). ... At 240Frames/sec the strobe was seen in two frames (multiple times). 1./240 =4.1 millisecond. ... The strength of the strobe lights was not the same in the two frames, so part of the duration may be that the two strobes are not exactly synchronized . ...

Static Fourier spectrometers are often used for spectral measurements of the ionosphere emissions. There are two main advantages of Fourier spectrometers (FS) - large geometric factor and high spectral resolution; these parameters are two orders better than for grating spectral instruments. ... In scanning Fourier spectrometer optical and electric modulation of signal is used to avoid this problem, for static Fourier spectrometer there are no such ways. ...

RTT150 . Russian-Turkish 1.5-m Telescope . ... Telescope has two main foci (Cassegrain and Coude ) and allows to use six optical systems based on Ritchey-Chretien system with a common main mirror . At present scientific observations are being performed at the Cassegrain focus in main optical scheme with focal ratio of 1:7.7. ... flat . ... To use the Coude focus the removable flat diagonal mirror is also needed in the crossing point of declination axis and main optical axis of telescope. ...

Peremennye Zvezdy", . ... We present the historical light curve of NGC 4151 for 1906 - 2007. The light curve is primarily based on our published photoelectric data (1968 - 2007, about 1040 nightly mean measurements) and photographic estimates (mostly Odessa and Moscow plates taken in 1906 - 1982, about 350 measurements; Oknyanskij 1977, 1978, 1983). ... 1983) (Harvard and Steward observatories' patrol plates taken in 1910 - 1968, about 210 measurements). ... Light Curve . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The light curves of AM CVn systems obtained using the Liverpool Telescope which showed an outburst. We show the start date of the observations in the top right of each panel and the orbital period of each system towards the right. ... The orbital period of the outbursting systems lie in the range 24тАУ44 mins and is remarkably consistent with disk-instability predictions. ... Systems which have short periods ( . ...

... 2013 January 17 . Cas A: Optical and X-ray . Image Credit: X-ray - NASA , JPL-Caltech, NuSTAR ; Optical - Ken Crawford ( Rancho Del Sol Obs. Explanation: The aftermath of a cosmic cataclysm, supernova remnant Cassiopeia A (Cas A) is a comfortable 11,000 light-years away. ... The sc