... 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 this activity, students will observe that the faintest stars which they can see in the sky are affected by many things: the adaptation of their eyes to the dark, the presence of clouds or haze, the time of year, and the presence of light pollution. General Information . ... After completing this activity, students should have a better understanding of the practical processes for dealing with the light pollution problem and with other environmental and societal issues. << previous page | ...

SN 1989B Light Curve Analysis. ... In the light curve depicting their observations, definite trends are noted, here is a "thumb-nail" analysis of the the magnitude estimations of the bright SN (1989B) in the galaxy NGC 3627 (M66). ... The observations were inserted against the V magnitude templete of BL, CCD photometric data, (Wells et. al, (1994) and a color trend (B-V) histogram of the mean type Ia SN (BL)(nutemp.gif). Key Words: Amateur Observations, Supernova, Magnitude Estimates, 1989B . ...

... Tonight's Sky . ... SUN MOON MERCURY VENUS MARS, JUPITER SATURN . ... Observing . ... Astronomy for Kids . ... Get to Know the Night Sky . ... Sky-event alert: Venus, brightest light in the night sky . All month, Earth's sister world appears high and bright in the night sky after sunset for easy viewing. ... January's celestial night-light is Venus. ... More resources from Astronomy.com: . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... 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. ...

... ESO is building what will be the World's largest optical telescope array, The Very Large Telescope (VLT). The VLT Project organisation is responsible for the design and construction of the Unit Telescopes, including enclosures, optics, adapter-rotators and coating unit. ... Unit Telescopes Overview - This page is outdated, an update is in process. ... Secondary mirror (M2 Unit) - This page is outdated, an update is in process. ... Coating Unit - This page is outdated, an update is in process. ...

... Usually, the reflection of city lights off of local air impurities makes it hard for casual observers to see more than a handful of stars from a bright urban area . ... Prominent in the above four-image digital montage are two of the few celestial wonders that can be seen even above the usual glare of city light pollution : the Moon and Mars . ... Scrolling right will show how eerily dark New York City appeared from across the Hudson River in New Jersey at about 10 pm on 2003 August 14. ... August ....

... a greenish glow is often seen in the sky, known as the "Northern Lights." ... During magnetic storms, the glow may move southwards, and on occasion it can be seen in much of the US. ... A similar phenomenon is also seen in southern polar regions. ... Auroral light is produced at a height of about 100 km (60 miles) when fast electrons, arriving from space, slam into atoms and molecules of the atmosphere. ... The green light of the aurora puzzled scientists for many years, since it fit no known...

... Note: Click here a longer, much more comprehensive overview of the polar aurora . ... Magnetic Field . ... Aurora . ... 3b. Fritz Aurora . ... Electrons . ... Typical aurora (Dick Hutchinson ї) . In Alaska, Canada, Norway, Finland or northern Russia, on a clear night, a greenish glow is often seen in the sky, known as the "Northern Lights." ... Auroral light is produced at a height of about 100 km (60 miles) when fast electrons, arriving from space, slam into atoms and molecules of the atmosphere. ...

... From the peculiar shape of the light curve in the visible spectral region (a long phase interval of light constancy was observed by Hensberge et al. in 1981 ), HD 56022 had been expected to show unambiguously the nonequatorial symmetry of its surface brightness distribution. However, analysis of the light curve has yielded a possible equatorial position of a spot. ... A solution seems only possible, if the light constancy over the long phase interval in the visible is not observed in the UV. ...

... In the light curve depicting their observations, definite trends are noted, here is a "thumb-nail" analysis of the the magnitude estimations of the bright SN (1989B) in the galaxy NGC 3627 (M66). ... 10 (IAUC # 4742) 2/25 13.3 16 j 2/27 13.5(*) 18 lc 2/28 13.8 19 p 3/1 13.2 20 w 3/2 13.5 21 a 3/4 13.8 23 p 3/6 13.3 25 c 3/7 13.3 26 c 3/8 14.1 27 m 3/8 13.3 27 r 3/9 13.4 28 c 3/9 14.1 28 m 3/10 13.6 29 j 3/10 14.0 29 a 3/11 13.6 30 c 3/11 13.5 30 r 3/11 13.7 30 s 3/13 [13.69 CCD Mag.] ...

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. ...

We have analyzed dimmings (i.e. transient coronal holes) and manifestations of a . coronal wave in the famous event of 14 July 2000 using images produced with the EUV . telescope SOHO/EIT. ... this event was studied using running -difference EIT images at 195 formed by the . ... Running -difference images . ... fixed -difference images are considered. ... 171, 195, 284, and 304 , as well as the light curves of the main dimmings including . several later images at 195 . To event page ...

Measurement of Sky Brightness at the Iranian National Observatory Davoud Afshari1 and Sadollah Nasiri1,2 1Physics Department, Zanjan University, Zanjan 45195-313, Iran; Institute for Advanced studies in Basic Science (IASBS), Zanjan 45195-1159, Iran; Measurement of light pollution 2 Introduction Among 34 candidate sites at the central part of the country, 5 sites namely Garkesh (in Kashan ), Kolahbarfi(in Kashan ), Deynava (in ... One of these is light pollution. ...

... BLUE STRAGGLER STARS are unusually hot and bright stars found in the cores of ancient star clusters known as globulars. ... BACKGROUND (from wikipedia): Blue straggler stars are stars in open or globular clusters that are hotter and bluer than other cluster stars having the same luminosity. ... There is evidence in favor of this view, notably that blue straggler stars appear to be much more common in dense regions of clusters, especially in the cores of globular clusters. ...

... Kashyap, V., Drake, J., Smith, R., & Wargelin, B., 2014, 15 Years of Science with Chandra Symposium, Spectrum Ultimum Capellae: XV Years of Chandra Observations of Capella . ... Kashyap, V.L., Connors, A., Drake, J., Lee, T., Posson-Brown, J., Saar, S., Scargle, J., van Dyk, D., & Wong, R., 2014, AAS/HEAD 14, 119.05 TANAGRA: Timing Analysis of Grating Data . ... Audard, M., G del, M., Drake, J.J., & Kashyap, V.L., 2000, ApJ, 541, 396 . Audard, M., G del, M., & Guinan, E.F., 1999, ApJ, 513, L53 . ...

Please enter the lightcurve file name and period search parameters: . Lightcurve file: . ... Apply the Heliocentric correction and convert all dates to Terrestrial Time (TT)? ... Also, the Heliocentric correction cannot be applied to such lightcurves. ... This period search service is also available at the mirror sites: Mirror 1 , Mirror 2 , Mirror 3 , Mirror 4 . You may download the latest source code distribution and install the period search service at your own web server. ...

... 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. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Stars . ... Starbursts are short-lived events, stars are forming so quickly that the reservoirs of interstellar gas from which stars are coalescing would be used up on a timescale much shorter than the age of the galaxy . ... Strong stellar winds from giant new stars in the starburst region combine with the blasts of supernovae to push a mighty flood of extremely hot gas, a ?superwind? from the galaxy thousands of light years into intergalactic space. ...

XMM-Newton Science Analysis System . ... Meta Index / Home Page Further enhancements may be necessary in the light of in-flight experience, eg. location of the source within the camera field-of-view, to avoid CCD boundaries) . the nearest-neighbour distance threshold may need to be a function of source brightness, to alleviate problems with multiple detection of bright sources (this depends on the performance of the source detection software) . XMM-Newton SOC/SSC -- 2005-08-16 ...