* Astronomy

Blobrana · L

RE: RR Pictoris

Blobrana · L

RR Pictoris is a cataclysmic variable star system that was first noticed by South African astronomer R. Watson on 25 May 1925 when it had an apparent magnitude of 2.3.
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Blobrana · L

RR Pictoris is a cataclysmic variable located 1.5° west southwest of Alpha Pictoris, that flared up as a nova, reaching magnitude +1.2 in on 9 June 1925. It is a close binary system composed of a white dwarf and secondary star that orbit each other every 3.48 hours - so close that the secondary is filling up its Roche lobe with stellar material, which is then transferred onto the first star's accretion disc. Once this material reaches a critical mass, it ignites and the system brightens tremendously. Calculations of the speed suggest the secondary star is not dense enough for its size to still be on the main sequence, so it itself must have begun expanding and cooling already as its core has run out of hydrogen fuel.

Blobrana · L

RR Pictoris reached an apparent magnitude 1.2 in on the 9th June, 1925.

Blobrana · L

NOVA Pic 1925 -- Nova

Position(2000): RA 06 35 36.0645, Dec -62 38 24.298

Blobrana · L

Title: RR Pictoris: an old nova showing superhumps and QPOs
Authors: L. Schmidtobreick, C. Papadaki, C. Tappert, A. Ederoclite

We present time-resolved V-photometry of the old nova RR Pic. Apart from the hump-like variability, the light curves show the strong flickering and random variation typical for RR Pic. We do not find any convincing evidence for the previously reported eclipse. The extrapolated eclipse phase coincides with a broad minimum, but comparing the overall shape of the light curve suggests that the eclipse should actually be located around phase 0.2. The orbital period which we derive from these data agrees well with the old one, any uncertainty is too small to account for the possible phase shift. Apart from the 3.48h period, which is usually interpreted as the orbital one, we find an additional period at P=3.78h, which we interpret as the superhump period of the system; the corresponding precession period at 1.79d is also present in the data. We also find indications for the presence of a 13min quasi-periodic oscillation.

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Blobrana · L

Pic 1925 -- Nova
RR Pictoris was a nova, which lit up in the constellation Pictor in 1925. RR Pictoris reached a brightness of 1.2 mag. The brightness of RR Pictoris decreased in 150 days by 3 mag. Today RR Pictoris has a brightness of 9 mag.

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RR Pictoris.kmz

Google Sky file (1kb, KMZ)

Position(2000): RA 06 35 36.0645, Dec -62 38 24.298

Blobrana · L

Title: RR Pic (1925): A Chandra X-ray View
Authors: Y. Pekon, S. Balman (METU)

We present the Chandra ACIS-S3 data of the old classical nova RR Pic (1925). The source has a count rate of 0.067+/-0.002 c/s in the 0.3-5.0 keV energy range. We detect the orbital period of the underlying binary system in the X-ray wavelengths. We also find that the neutral Hydrogen column density differs for orbital minimum and orbital maximum spectra with values 0.25(+0.23-0.18)x10^22 cm^-2 and 0.64(+0.13-0.14)x10^22 cm^-2 at 3sigma confidence level. The X-ray spectrum of RR Pic can be represented by a composite model of bremsstrahlung with a photoelectric absorption, two absorption lines centred around 1.1-1.4 keV and 5 Gaussian lines centred at emission lines around 0.3-1.1 keV corresponding to various transitions of S, N, O, C, Ne and Fe . The bremsstrahlung temperature derived from the fits range from 0.99 to 1.60 keV and the unabsorbed X-ray flux is found to be 2.5(+0.4-1.2)x10^-13 erg cm^-2 s^-1 in the 0.3-5.0 keV range with a luminosity of (1.1\pm0.2)x10^31 erg s^-1 at 600 pc. We also detect excess emission in the spectrum possibly originating from the reverse shock in the ejecta.

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