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Limits on the short-timescale near-infrared variability of Seyfert 1 nuclei
We present new time-resolved photometric observations and images at 2.2microns of a small sample of X-ray variable Seyfert 1 nuclei. Aftercorrecting for dilution by the host galaxy in the observing aperture, wecompare the fractional variation, over the timescales of theobservations, in the near-infrared (NIR) to that expected in the X rays.We have not detected with confidence any NIR variability on timescalesshort enough to be incompatible with the dust reradiation scenario. Thegalaxy-corrected upper limits which we have obtained for variations onshort timescales, typical of non-thermal processes, imply that the NIRemission is dominated by a slowly varying, presumably reprocessed,component which accounts for no less than 80%-90% of the total.
| Common proper motion stars in the AGK 3
A search was made of common-proper-motion (CPM) systems among AGK 3stars. The selection of physical systems was based upon the ratiobetween the angular separation (rho) and the proper motion (mu); the CPMstars found are presented in two tables. Table I lists systems withrho/mu less than 1000 years. It contains 326 entries, and the proportionof optical pairs is estimated to be 1 percent. Table II lists systemswith rho/mu in the range 1000 to 3500 years; it contains 113 systems,but only 60 percent of them are physical. Nevertheless, these systemsoften have separations larger than 10,000 AU and are the mostinteresting for the study of the tail of the distribution function ofthe semimajor axes.
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Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Aslan |
| Sað Açýklýk: | 10h21m50.01s |
| Yükselim: | +21°20'49.2" |
| Görünürdeki Parlaklýk: | 9.158 |
| özdevim Sað Açýklýk: | -53.8 |
| özdevim Yükselim: | -19.4 |
| B-T magnitude: | 9.628 |
| V-T magnitude: | 9.197 |
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