Position of Nova Geminorum, 1912

Optical spectroscopy of the dwarf nova U Geminorum

The dwarf nova U Gem is unique in having a direct measurement of the K-velocity of its white dwarf from HST spectra (K 1 = 107 ± 2 km s −1 , Long et al. 1999). We present high-resolution optical spectra of the dwarf nova U Gem in quiescence taken to test the accuracy to which the HST value can be recovered from optical data. We find that, even with data of very high signal-to-noise ratio on thi...

Nova Geminorum No. 2 as a Wolf-Rayet Star.

It has been known for many years that the spectrum of temporary stars or Novae develops in a later stage into a spectrum nearly identical with that of planetary nebulae. First observed in the case of Nova Aurigae of 1891, the same result has been found to hold for all of the temporary stars observed since that time, including the most important Nova of recent years, Nova Persei of 1901. The que...

Idea of Gravitational Lensing

Einstein’s early calculations of gravitational lensing, contained in a scratch notebook and dated to the spring of 1912, are reexamined. A hitherto unknown letter by Einstein suggests that he entertained the idea of explaining the phenomenon of new stars by gravitational lensing in the fall of 1915 much more seriously than was previously assumed. A reexamination of the relevant calculations by ...

An Irradiation Effect in Nova DN Gem 1912 and the Significance of the Period Gap for Classical Novae

Continuous CCD photometry of the classical nova DN Gem during 52 nights in the years 1992-98 reveals a modulation with a period 0.127844 d. The semi-amplitude is about 0.03 mag. The stability of the variation suggests that it is the orbital period of the binary system. This interpretation makes DN Gem the fourth nova inside the cataclysmic variable (CV) period gap, as defined by Diaz & Bruch (1...

Michael Abercrombie (1912-1979).