1,721,041 research outputs found
Wind accretion in KQ Puppis
No full textFrom a multiwavelength long term monitoring of KQ Pup, we derive a revised orbital period of 9500 days. The presence of an accreting stream is put in evidence by a large decrease of the FUV continuum due to Rayleigh scattering, and by the appearance of redshifted absorptions since Φ = 0.82
Digitizing the Markarian Survey: first tests of scientific importance
No full textWe present technical details of the digitization of the First Byurakan Survey plates with an EPSON 1680 Pro scanner, a joint venture of the Rome University and the Byurakan Observatory. The astronomical coordinate system is applied to each plate by a semi-automatic procedure, the transparency converted to intensity and all the spectra in each plate automatically extracted by IRAF procedures. A first check of the photometric accuracy achieved is presented
SPECTRA IN THE DIGITIZED FIRST BYURAKAN SURVEY
No full textThe Digitized First Byurakan Survey (DFBS) is accessible on a dedicated web site at the Department of Physics of La Sapienza University. It covers about 17 000 square degrees and provides low resolution spectra of sources down to B = 16.5 mag. Both the digitized plates and the automatically extracted spectra can be retrieved. We present the main characteristics of the spectra and their relevance as proxies for the low dispersion spectra which will be provided by the forthcoming Gaia mission. Detectability of spectral features, overall spectral energy distribution and accuracy of the photometric information is briefly discussed
3C 345: The historical light curve (1967-1990) from the digitized plates of the Asiago Observatory
No full textAs part of a large project to digitize the plate archives of the Italian and Vatican Astronomical Observatories, we have already performed the digitization of all available plates of the field of the quasar 3C 345. The plates, approximately 100 in number, were taken with the three telescopes of the Asiago Observatory (122 cm, 182 cm, 67/90 cm Schmidt Telescope) in the period from 1967 to 1990. We present here essentially new data, mostly in the B band, about the variability of 3C 345 and also of four other objects (three quasars - Ql, Q2 and Q3 - and the active galaxy NGC 6212) in the same field, in that period. Beyond the well-known 3C 345 itself, the other three quasars also show variability, with a range of 2.0 mag for Ql and Q2, and 1 mag for Q3. The low-level variability detected for the nucleus of NGC 6212 is more doubtful, and should be confirmed by linear detector data
Optical Activity of HDE 245770/A0535+26 System
No full textThe O9.7IIIe star HDE 245770, nicknamed Flavia, is the optical counterpart of the X-ray pulsar A0535+26. On February 5, 2011 at the Loiano 1.52 m telescope from UT 18hh 40mm 40ss we performed optical B, V spectrophotometry of HDE 245770 and starting from UT 18hh 51mm 11ss to 19hh 15mm 37ss we performed optical spectroscopy in the range 330 - 785 nm [Delta(lambda) from about 0.4 to 0.3 nm] by using the BFOSC (Bologna Faint Object Spectrograph & Camera)
A pre-outburst spectrum of KT Eri from the Digitized First Byurakan Survey (DFBS)
No full textA historical spectrum, taken on Jan 25 1971, of the recently exploded Nova KT Eri is recorded on the plate n. 0350 of the First Byurakan Survey (FBS). This Survey was made with a thin objective prism atop the 102/130/213 cm Schmidt telescope of the Byurakan Observatory and IIaF emulsion, covering the wavelength range 3400-6900 A. Nearly all the plates of this Survey (a.k.a Markarian Survey) have been digitized by a collaboration of the Byurakan Observatory, University La Sapienza, Rome Italy, and Cornell University (USA)
The TACOR educational telescope and the Italian RemoteLab Project - Learning tools for the International Year of Astronomy 2009
No full textThe Department of Physics of La Sapienza University has installed a didactic remote controlled telescope (TACOR) which, in collaboration with the Department of Physics of University Roma Tre, is currently used by mid-level and high-school classes. TACOR operates in the framework of the National RemoteLab Project which is supported by Italian Ministry of Public Education. During the forthcoming IYA2009, TACOR and RemoteLab will be powerful online tools for an interdisciplinary teaching and public communication of astronomy
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