RR Pictoris

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RR Pictoris
RRPicLocation.png
Location of RR Pictoris (circled in red)
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Pictor
Right ascension 06h 35m 36.063s [1]
Declination −62° 38 22.29 [1]
Apparent magnitude  (V)1.2Max.
12.5Min.
Astrometry
Distance 1,670+26
26
  ly
(511+8
−8
[2]   pc)
Characteristics
Variable type Classical Nova
Other designations
RR Pic, HIP  31481, TYC  8899-1342-1, Nova Pic 1925, AAVSO 0634-62, Gaia DR2 5477422099543150592
Database references
SIMBAD data
The light curve of RR Pictoris from AAVSO data. RRPictorisLightCurve.png
The light curve of RR Pictoris from AAVSO data.
The early portion of the light curve of RR Pictoris, showing the three brightness peaks which were seen shortly after the nova's discovery. Plotted from AAVSO data. RRPictorisEarlyLightCurve.png
The early portion of the light curve of RR Pictoris, showing the three brightness peaks which were seen shortly after the nova's discovery. Plotted from AAVSO data.

RR Pictoris, also known as Nova Pictoris 1925, is a cataclysmic variable star system that flared up as a nova that lit up in the constellation Pictor in 1925. It was discovered by South African amateur astronomer R. Watson who lived in Beaufort West. At 05:50 AM on 25 May 1925, Mr. Watson was walking to work and noticed a star that he did not recognize in line with the stars α Crucis and β Carinae. He consulted his copy of Norton's Star Atlas, and realized that the unfamiliar star was a nova. Fortuitously, Mr. Watson was employed as a telegraph operator, and he promptly sent a telegram describing his discovery to the Royal Observatory at Cape Town. This quick reporting of the event allowed southern observatories to obtain spectra of the nova before it had reached maximum brightness. [3] [4]

At the time of its discovery, RR Pictoris had an apparent magnitude of 2.3. It continued to brighten to magnitude 1.2, which it reached on 9 June 1925. It dimmed to magnitude 4 by 4 July, but brightened again to 1.9 on 9 August. Six months after its peak brightness, RR Pictoris faded to be invisible to the unaided eye, and was magnitude 12.5 by 1975. [5] RR Pictoris is classified as a slow nova [6] and its light curve exhibits positive superhumps, meaning superhumps with a period a few percent (8.6% in this case) longer than the star system's orbital period. [7]

Measurements by the Gaia spacecraft show that the RR Pictoris system is around 510 parsecs (1670 light-years) from the Earth. [2]

Novae are close binary systems composed of a white dwarf and secondary star that is so close it 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. The two stars of RR Pictoris orbit each other every 3.48 hours. 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. [8]

Small variations in the observed orbital period suggest that RR Pictoris system may include a low mass (0.25 M) third star orbiting the close binary pair with a period of about 70 years. [9]

A small (< 30 arc second) filamentary nebula surrounds the nova, and comparisons of images taken several years apart have allowed its rate of expansion to be measured. [10] [11]

Related Research Articles

<span class="mw-page-title-main">Pictor</span> Constellation in the southern celestial hemisphere

Pictor is a constellation in the Southern Celestial Hemisphere, located between the star Canopus and the Large Magellanic Cloud. Its name is Latin for painter, and is an abbreviation of the older name Equuleus Pictoris. Normally represented as an easel, Pictor was named by Abbé Nicolas-Louis de Lacaille in the 18th century. The constellation's brightest star is Alpha Pictoris, a white main-sequence star around 97 light-years away from Earth. Pictor also hosts RR Pictoris, a cataclysmic variable star system that flared up as a nova, reaching apparent (visual) magnitude 1.2 in 1925 before fading into obscurity.

<span class="mw-page-title-main">V604 Aquilae</span> Nova in the constellation Aquila

V604 Aquilae or Nova Aquilae 1905 is a nova which was first observed in the constellation Aquila in 1905 with a maximum brightness of magnitude 7.6. It was never bright enough to be seen with the naked eye. It was discovered by Williamina Fleming on a Harvard College Observatory photographic plate taken on August 31, 1905. Examination of plates taken earlier indicates that peak brightness occurred in mid-August 1905. The star's quiescent visual band brightness is 19.6.

<span class="mw-page-title-main">NQ Vulpeculae</span> 1976 Nova seen in the constellation Vulpecula

NQ Vulpeculae also known as Nova Vulpeculae 1976, was a nova that appeared in the constellation Vulpecula in 1976. It was discovered visually at 18:20 UT on October 21, 1976 by English amateur astronomer George Alcock. Its apparent magnitude at the time of discovery was 6.5 It reached its maximum brightness of magnitude 6.0 thirteen days after its discovery, at which point it may have been faintly visible to the naked eye. A few days after maximum brightness, it had faded to magnitude 8.3.

<span class="mw-page-title-main">V838 Herculis</span> 1991 Nova seen in the constellation Hercules

V838 Herculis, also known as Nova Herculis 1991, was a nova which occurred in the constellation Hercules in 1991. It was discovered by George Alcock of Yaxley, Cambridgeshire, England at 4:35 UT on the morning of 25 March 1991. He found it with 10×50 binoculars, and on that morning its apparent visual magnitude was 5. Palomar Sky Survey plates showed that before the outburst, the star was at photographic magnitude 20.6 and 18.25.

<span class="mw-page-title-main">V842 Centauri</span> Nova in the constellation Centaurus seen in 1986

V842 Centauri, also known as Nova Centauri 1986, was a nova which occurred in 1986 in the constellation Centaurus. It was discovered by Robert H. McNaught of Siding Spring Observatory in Australia, on 22 November 1986. At the time of its discovery, it had an apparent magnitude of 5.6. It reached a peak magnitude of 4.6 one and a half days later, making it easily visible to the naked eye.

<span class="mw-page-title-main">V1059 Sagittarii</span> Nova seen in 1898 in the constellation Sagittarius

V1059 Sagittarii was a nova, which lit up in 1898 in the constellation Sagittarius. The star reached apparent magnitude 4.5, making it easily visible to the naked eye. It was discovered on 8 March 1898, by Williamina Fleming on a photographic plate taken at the Harvard College Observatory. The discovery plate was an objective prism plate, part of the Henry Draper Memorial Photographs, and Ms Fleming identified it as a nova based on its spectral characteristics.

<span class="mw-page-title-main">V606 Aquilae</span> 1899 nova in the constellation Aquila

V606 Aquilae was a nova, which lit up in the constellation Aquila in 1899. The brightest reported magnitude for this nova was apparent magnitude 5.5, making it a naked eye object. It was discovered by Williamina Fleming on a photographic plate taken on 21 April 1899 at the Harvard College Observatory. On the discovery plate, its photographic magnitude was later determined to be 6.75. It was not seen on the plate taken on 1 November 1898, and there were no reported observations of the region around the star during the 171 day interval before Fleming's discovery, so it is possible that the actual maximum of the event was missed. By 27 October 1899 it had faded to 10th magnitude, and on 9 July 1900 Oliver Wendell reported its brightness to be between magnitude 11.5 and 12.0.

<span class="mw-page-title-main">Dwarf nova</span> Cataclysmic variable star, consisting of a close binary star system

A dwarf nova, or U Geminorum variable, is one of several types of cataclysmic variable star, consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from its companion. Dwarf novae are dimmer and repeat more frequently than "classical" novae.

<span class="mw-page-title-main">RW Ursae Minoris</span> Nova that appeared in 1956

RW Ursae Minoris is a cataclysmic variable star system that flared up as a nova in the constellation Ursa Minor in 1956.

<span class="mw-page-title-main">HR Delphini</span> 1967 Nova seen in the constellation Delphinus

HR Delphini, also known as Nova Delphini 1967, was a nova which appeared in the constellation Delphinus in 1967. It was discovered by George Alcock at 22:35 UT on 8 July 1967, after searching the sky for over 800 hours with binoculars. At the time of discovery it had an apparent magnitude of 5.0. It reached a peak brightness of magnitude 3.5 on 13 December 1967, making it easily visible to the naked eye around that time. Pre-outburst photographs taken with the Samuel Oschin telescope showed it as a ~12th magnitude star which might have been variable.

<span class="mw-page-title-main">V1017 Sagittarii</span> Star in the constellation Sagittarius

V1017 Sagittarii is a cataclysmic variable star system in the constellation Sagittarius. It first erupted in 1919, reaching magnitude 7. Its other eruptions in 1901, 1973 and 1991 only reached magnitude 10, leading it to be reclassified from a recurrent nova to a dwarf nova.

SW Sextantis variable stars are a kind of cataclysmic variable star; they are double-star systems in which there is mass transfer from a red dwarf to a white dwarf forming a stable accretion disc around the latter. Unlike other non-magnetic cataclysmic variables, the emission lines from hydrogen and helium are not doubled, except briefly near phase 0.5.

<span class="mw-page-title-main">Q Cygni</span> 1876 Nova in the constellation Cygnus

Q Cygni, is a star located in the constellation Cygnus. It is also known as Nova Cygni 1876, and has the designation NGC 7114, and HR 8296. Nova Cygni is located in the northwestern portion of Cygnus along the border with Lacerta.

<span class="mw-page-title-main">Superhump</span>

In astronomy, a superhump is a periodic brightness variation in a cataclysmic variable star system, with a period within a few percent of the orbital period of the system.

<span class="mw-page-title-main">SU Ursae Majoris</span> Variable star in the constellation Ursa Major

SU Ursae Majoris, or SU UMa, is a close binary star in the northern circumpolar constellation of Ursa Major. It is a periodic cataclysmic variable that varies in magnitude from a peak of 10.8 down to a base of 14.96. The distance to this system, as determined from its annual parallax shift of 4.53 mas, is 719 light-years. It is moving further from the Earth with a heliocentric radial velocity of +27 km/s.

<span class="mw-page-title-main">V630 Sagittarii</span> Nova that appeared in 1936

V630 Sagittarii was a nova visible to the naked eye in 1936. It was discovered on 3 October 1936 by Shigeki Okabayashi of Kobe, Japan when it had an apparent magnitude of 4.5.

<span class="mw-page-title-main">V728 Scorpii</span> Nova seen in 1862

V728 Scorpii, also known as Nova Scorpii 1862, was a nova that occurred in the constellation of Scorpius. It was discovered on 4 October 1862 by John Tebbutt, an astronomer living in New South Wales, Australia, while he was observing a comet. He reported that the star was in the constellation Ara. At the time of its discovery, the nova had an apparent magnitude of 5, making it visible to the unaided eye. Nine days later it had faded to below 11th magnitude, indicating that it was a very fast nova.

<span class="mw-page-title-main">WY Sagittae</span> 1783 Nova seen in the constellation Sagitta

WY Sagittae, also known as Nova Sagittae 1783, is a star in the constellation Sagitta which had a nova eruption visible in 1783. It was discovered on 26 July 1783 by the French astronomer Joseph Lepaute D'Agelet. It is usually difficult to precisely identify novae that were discovered hundreds of years ago, because the positions were often vaguely reported and historically there was not a clear distinction drawn between different sorts of transient astronomical events such as novae and comet apparitions. However D'Agelet observed this nova with a mural quadrant, which produced coordinates accurate enough to allow modern astronomers to identify the star. D'Agelet reported the apparent magnitude of the star as 6, but Benjamin Apthorp Gould, who analysed D'Agelet's records, determined that what D'Agelet called magnitude 6 corresponds to magnitude 5.4 ± 0.4 on the modern magnitude scale, so the nova was visible to the naked eye.

<span class="mw-page-title-main">BZ Ursae Majoris</span> Dwarf Nova in the constellation Ursa Major

BZ Ursae Majoris is a dwarf nova star system in the northern circumpolar constellation of Ursa Major. It consists of a white dwarf primary in a close orbit with a red dwarf. The latter star is donating mass, which is accumulating in an accretion disk orbiting the white dwarf. The system is located at a distance of approximately 505 light years from the Sun based on parallax measurements.

<span class="mw-page-title-main">ER Ursae Majoris</span> Variable binary star system in the constellation Ursa Major

ER Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, abbreviated ER UMa. It is a prototype system for a subclass of SU Ursae Majoris dwarf novae. The system ranges in brightness from a peak apparent visual magnitude of 12.4 down to 15.2, which is too faint to be visible to the naked eye. The distance to this system, based on parallax measurements, is approximately 1,163 light years.

References

  1. 1 2 "RR Pic". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 5 December 2020.
  2. 1 2 Schaefer, Bradley E. (20 September 2018). "The distances to Novae as seen by Gaia". Monthly Notices of the Royal Astronomical Society. 481 (3): 3033–3051. arXiv: 1809.00180 . Bibcode:2018MNRAS.481.3033S. doi: 10.1093/mnras/sty2388 .
  3. Vandenbos, W.H. (1947). "Nova Pictoris 1925". Monthly Notes of the Astronomical Society of South Africa. 6: 2–4. Bibcode:1947MNSSA...6....2V . Retrieved 5 December 2020.
  4. Barritt, Leon (February 1926). "Nova Pictoris, 1925". The Monthly Evening Sky Map. XXI: 1.
  5. Burnham, Robert (2013) [1977]. Burnham's Celestial Handbook, Volume Three: An Observer's Guide to the Universe Beyond the Solar System. New York, New York: Courier Dover Publications. pp. 1460–62. ISBN   978-0-486-31803-5.
  6. "RR Pictoris". aavso.org. American Association of Variable Star Observers. Retrieved 5 December 2020.
  7. Fuentes-Morales, I.; Vogt, N.; Tappert, C.; Schmidtobreick, L.; Hambsch, F.J.; Vuckovic, M. (February 2018). "Photometric long-term variations and superhump occurrence in the Classical Nova RR Pictoris". Monthly Notices of the Royal Astronomical Society. 474 (2): 2493–2501. arXiv: 1710.06543 . doi: 10.1093/mnras/stx2838 .
  8. Ribeiro, Fabíola M. A.; Diaz, Marcos P. (2006). "A Tomographic Study of the Classical Nova RR Pictoris". Publications of the Astronomical Society of the Pacific. 118 (839): 84–93. arXiv: astro-ph/0510042 . Bibcode:2006PASP..118...84R. doi:10.1086/498458. JSTOR   498458. S2CID   18244357.
  9. Vogt, N.; Schreiber, M.R.; Hambsch, F.J.; Retamales, G.; Tappert, C.; Schmidtobreick, L.; Fuentes-Morales, I. (January 2017). "The Orbital Ephemeris of the Classical Nova RR Pictoris: Presence of a Third Body?". Publications of the Astronomical Society of the Pacific. 129 (971): 014201. arXiv: 1609.05274 . Bibcode:2017PASP..129a4201V. doi:10.1088/1538-3873/129/971/014201. S2CID   119183582.
  10. Williams, R.E.; Gallagher, J.S. (March 1979). "Spectrophotometry of filaments surrounding nova RR Pictoris 1925". The Astrophysical Journal. 228: 482–490. Bibcode:1979ApJ...228..482W. doi: 10.1086/156869 . Retrieved 5 December 2020.
  11. Duerbeck, H.W. (December 1987). "The large intractable nova shells". The Messenger. 80: 8–11. Bibcode:1979ApJ...228..482W. doi: 10.1086/156869 . Retrieved 5 December 2020.