The Application of a Thermionic Amplifier to the Photometry of Stars
1932; IOP Publishing; Volume: 76; Linguagem: Inglês
10.1086/143416
ISSN1538-4357
Autores Tópico(s)Calibration and Measurement Techniques
Resumoview Abstract Citations (6) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Application of a Thermionic Amplifier to the Photometry of Stars Whitford, Albert E. Abstract A tizermionic amplifier employing the FP-54 Pliotron tube for amplification of photo- electric currents in stellar photometry is described. A marked improvement in stability has been attained by evacuating the space around the photo-electric cell and amplifier tube. The least curre~it which can be detected is approximately 1.1 >( io-~ amp., which cor- responds to the light-effect from a star of magnitude 14.3 at the focus of the 15-inch refractor, using a potassium-hydride cell by Jacob Kunz. As the amplification factor is about 2,200,000, such currents can be measured with a galvanometer. It is possible to observe stars of magnitude 9.0 with a probable error of not over ± 0.03 mag. for one deflection, and brighter stars with greater precision. Preliminary results for W Ursae Majoris and e Lyrae, obtained by Messrs. Stebbins and Huffer, with the `5-inch telescope of the Washburn Observatory, are included to show the pos- sibilities of the instrument Publication: The Astrophysical Journal Pub Date: November 1932 DOI: 10.1086/143416 Bibcode: 1932ApJ....76..213W full text sources ADS |
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