Next: Methods for Structuring and Searching Very Large Catalogs . ... We have explored two automated classification methods: supervised classification using Artificial Neural Networks (ANN) and unsupervised classification using Self Organized Maps (SOM). These methods are used to classify IUE low-dispersion spectra of normal stars with spectral types ranging from O3 to G5. This paper describes the application of automated methods to the problem of the classification of stellar spectra. ...

... exoplanets . ... Extreme life-forms might be able to survive on eccentric exoplanets . Research suggests that planets potentially hostile to human life might be the perfect place for extremophiles to survive. ... Although planets like these would be very different from Earth, this might not preclude them from being able to support alien life. т??Scientists have found microscopic life-forms on Earth that can survive all kinds of extreme conditions,т?? ... Kane said. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Comets and Asteroids . ... Earth Satellites . ... Thankfully, throughout the human species? life span falling asteroids or large impacts have not killed anyone. However, around 65 million years ago an asteroid or comet about 10km (6 miles) wide caused global extinction for around 70% of all life when it crashed into the Earth. ... It makes sense now to link the Chicxulub impact crater with a large asteroid that impacted 65 million years ago. ...

... Keck spectropolarimetry, giving spectral coverage from Ly- to beyond CIII], and HST imaging of a sample of powerful radio galaxies with has been obtained. ... This is a short progress report on a rather extensive programme we are carrying out to study the structure and composition of high redshift radio galaxies (HzRG) -- and, by implication, the host galaxies of radio quasars -- using observations in the optical, IR and mm bands. ... An example of the NICMOS and WFPC 2 imaging is shown in Figure 2 ...

... Ciel Espace, le magazine qui vous guide toujours plus loin . ... des actualit†йs . ... des interviews, des portraits . les plus belles images de l'Univers d†йcrypt†йes pour vous . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil †А la une Penser l'Univers aujourd'hui . ... Penser l'Univers aujourd'hui . ... Enqu†кte sur les curieux du ciel : lтАЩinventaire 2015 d†йmarre . ...

... ARC 3.5m | ... 2.1 Choosing and Exposure Time . 2.2 Choosing the CCD Gain . ... 3.2 Read Times and Read Noise . ... At the slow read rate of 100 KHz to be used for exposure times longer than a few seconds, we determine an average read noise of order 3.7 ? ... Table 2: Exposure time must be greater than the readout time by at least 0.03 s. The Agile CCD camera has two readout amplifiers, one of which is capable of reading at the fast readrate of 1MHz while introducing a read noise of order 7 ? ...