RS Ophiuchi

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**RS Ophiuchi A / B**
Observation data Epoch J2000.0
Recurrent nova RS Ophiuchus in eruption of February 2006
Constellation (pronunciation)	Ophiuchus
Right ascension	17^h 50^m 13.2^s
Declination	−06° 42′ 28″
Apparent magnitude (V)	9.6 - 13.5 (quiet), < 5 (burst)
Characteristics
Spectral type	M2III / White Dwarf
U-B color index	?
B-V color index	?
Variable type	Recurrent nova
Astrometry
Radial velocity (R_v)	? km/s
Proper motion (μ)	RA: ? mas/yr Dec.: ? mas/yr
Parallax (π)	? ± ? mas
Distance	1,950 — 5,200 ly ( 600^[1] — 1,600^[2] pc)
Absolute magnitude (M_V)	?
Other designations
HD 162214

RS Ophiuchi (RS Oph) is a nova approximately 5,000 light-years away in the constellation Ophiuchus. In its quiet phase it has an apparent magnitude of about 12.5. It erupted in 1898, 1933, 1958, 1967, 1985, and 2006 and reached about magnitude 5. The recurrent nova is produced by a white dwarf star and a red giant. About every 20 years, enough material from the red giant builds up on the surface of the white dwarf to produce a thermonuclear explosion. The white dwarf orbits within the distended atmosphere of the red giant, with an accretion disc concentrating the atmosphere of the red giant onto the white dwarf.

1 Novae
- 1.1 1898
- 1.2 1933
- 1.3 1958
- 1.4 1967
- 1.5 1985
- 1.6 2006
2 See also
3 Notes
4 Further reading
5 External links
- 5.1 In the news

[edit] Novae

[edit] 1898

The 1898 eruption was, in fact, not discovered until several years after it happened. Williamina Fleming discovered a nova-like spectrum in the Henry Draper Memorial photographs and announced it as a potential nova in 1904. This diagnosis was affirmed by Edward Pickering in 1905, after which Annie Jump Cannon determined that RS Ophiuchi had likely reached maximum in 1898.

[edit] 1933

The 1933 outburst was first detected by Eppe Loreta, from Bologna, Italy. Loreta had been observing Y Ophiuchi when he serendipitously noticed a bright object about 50 arcminutes southwest of Y Oph. The detection of this luminous star resulted in the second recorded outburst of RS Oph. An independent discovery of this activity was made several days later by Leslie Peltier (P) while making his routine check of the variable.

[edit] 1958

The 1958 outburst was detected by Cyrus Fernald, located in Longwood, Florida. Fernald's monthly report for July 1958, containing 345 observations, displays a note in which he comments "Not too good of a month outside of the RS Oph observations (19 in total). It was interesting to watch the change in color as the star faded. It was reddish-yellow the first night, then yellowish-red, and so on. The last observation was the reddist star that I have ever seen." The crimson color of which Mr. Fernald speaks is indicative of the strong H-alpha emission displayed in the several days following the outburst.

[edit] 1967

The 1967 outburst was again detected by Cyrus Fernald (FE), however, Fernald was not given credit for the earliest observation of maximum. For on the same evening, Dr. Max Beyer (BY), located in Hamburg, Germany, observed the variable at 6th magnitude. Due the 6-hour difference in time zones, Dr. Beyer was credited with the first report.

[edit] 1985

In January 1985, Warren Morrison of Peterborough, Canada discovered RS Oph to again be in outburst.

AAVSO light curve of RS Oph's 2006 outburst. Different colors reflect different bandpasses.

[edit] 2006

On February 12, 2006 a new outburst occurred, reaching magnitude 4.5. The opportunity was taken to observe it at different wavelengths.^[3]^[4]

[edit] See also

DM Lyrae

[edit] Notes

^ Izumi Hachisu and Mariko Kato, "A Theoretical Light-Curve Model for the 1985 Outburst of RS Ophiuchi", ApJ 536(2000), p. L93; Online abstract
^ Mariko Kato, "Theoretical light curve for the recurrent nova RS Ophiuchi - Determination of the white dwarf mass, composition, and distance", ApJ 369(1991), p. 471; Online abstract
^ Bode, MF; O'Brien, TJ; Osborne, JP; Page, KL; Senziani, F; Skinner, GK; Starrfield, S; Ness, J-U; Drake, JJ; Schwarz, G; Beardmore, AP; Darnley, MJ; Eyres, SPS; Evans, A; Gehrels, N; Goad, MR; Jean, P; Krautter, J and Novara, G (2006). "Swift Observations of the 2006 Outburst of the Recurrent Nova RS Ophiuchi. I. Early X-Ray Emission from the Shocked Ejecta and Red Giant Wind" (^{[dead link]}). The Astrophysical Journal 652 (1): 629–635. doi:10.1086/507980.
^ Monnier, JD; Barry, RK; Traub, WA; Lane, BF; Akeson, RL; Ragland, S; Schuller, PA; Le Coroller, H; Berger, JP; Millan-Gabet, R; Pedretti, E; Schloerb, FP; Koresko, C; Carleton, NP; Lacasse, MG; Kern, P; Malbet, F; Perraut, K; Kuchner, MJ; and Muterspaugh, MW (2006). "No Expanding Fireball: Resolving the Recurrent Nova RS Ophiuchi with Infrared Interferometry" (^{[dead link]}). The Astrophysical Journal 647 (2): L127–L130. doi:10.1086/507584.

[edit] Further reading

Sokoloski, J. L.; J. G. M. Luna, K. Mukai and Scott J. Kenyon (20 July 2006). "An X-ray-emitting blast wave from the recurrent nova RS Ophiuchi". Nature 442: 276–278. doi:10.1038/nature04893. (First paragraph; Editor's summary)
O'Brien, T. J.; M. F. Bode, R. W. Porcas, T. W. B. Muxlow, S. P. S. Eyres, R. J. Beswick, S. T. Garrington, R. J. Davis and A. Evans (20 July 2006). "An asymmetric shock wave in the 2006 outburst of the recurrent nova RS Ophiuchi". Nature 442: 279–281. doi:10.1038/nature04949. (First paragraph; Editor's summary)