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MWC 560

A light curve for MWC 560. The main plot, displaying the ASAS-3 data, shows the long term variability, and the inset plot, adapted from Marchev et al., shows the intermittent short timescale flickering.
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Monoceros
Right ascension	07 25 51.284
Declination	−07° 44′ 08.08″
Apparent magnitude (V)	9.70 (9.1 to 10.1)
Characteristics
Spectral type	M4ep + Beq
B−V color index	0.31
Astrometry
Proper motion (μ)	RA: 2.067 mas/yr Dec.: 0.552 mas/yr
Parallax (π)	0.424 ± 0.0352 mas
Distance	7,700 ± 600 ly (2,400 ± 200 pc)
Details
M-type giant
Mass	~1 M☉
White dwarf
Mass	0.9 M☉
Radius	6,221 km
Luminosity	200 to 3,000 L☉
Temperature	7,000–13,000 K
Other designations
MWC 560, V694 Mon, IRAS 07233-0737
Database references
SIMBAD	data

MWC 560 is a symbiotic binary star system in the equatorial constellation of Monoceros. The identifier comes from the Mount Wilson Calatogue of class O, B and A stars with bright hydrogen lines, published in 1933 by P. W. Merrill and associates. It has the variable star designation V694 Monoceros. This system has a typical apparent visual magnitude of 9.70, which is too dim to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 7,700 light years from the Sun.

Observations

N. Sanduleak and C. B. Stephenson included this in a list of objects in the southern Milky Way with strong emission lines in 1973. They found bands of TiO in the spectrum and indicators of variable emission lines. A stellar classification of M4ep was found. In 1984, H. E. Bond and associates classified this as a symbiotic binary system consisting of an M-type giant star with an orbiting compact companion. The profiles of absorption lines show changes on a day to day basis. They theorized that matter is being transferred from the M–giant at a higher rate than the companion is able to accrete it, producing a flickering appearance.

In 1990, absorption lines were found to be coming from high velocity components, possibly from a jet-like ejecta nearly along the line of sight. The high velocity aspect was confirmed by the IUE during an outburst, which suggested the ejection of a cool, optically-thick shell from the compact object. Velocities of up to 6,000 km/s were recorded, and during the outburst the brightness increased from magnitude 12.5 up to as high as 9.2. Meanwhile the emission lines showed a stable radial velocity. The high rate of mass transfer inferred that an accretion disk is orbiting the compact object, with a thick envelop hiding the inner disk and compact object from direct sight. This disk is probably perpendicular to the line of sight from Earth, so it is being viewed nearly face-on.

Observation of the system over a ten year period demonstrated a light variation with a period of 1,930 days, which may be explained by precessing of the disk. The system shifted between active and stable states, with outflow much higher during the active stage. Meanwhile, infrared observations in the i band suggested that the M-giant may undergo pulsations with a period of around 5 months. In 2007, this was refined to a period of about 340 days, making this a semiregular variable probably consisting of a thermally pulsing asymptotic giant branch star. X-ray emission was detected from this system in 2009, with the data being consistent with an accreting white dwarf source. It is accreting mass at a rate of (1 to 20)×10 M_☉·yr, with just a few percent of this rate being ejected in the jet.

The optical flickering persisted from 1984 until 2016. After a short pause it resumed until 2018, when it disappeared. At that point the system underwent steady brightness increase with periodicities of 331 and 1860 days. As of 2023, it remains in a non-flickering state, with maximum brightness achieved in October 2021.

References

1. "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 4 December 2024.
2. ^ Marchev, Dragomir; et al. (November 2022), "For optical flickering in symbiotic star MWC 560", Acta Scientifica Naturalis, 9 (3): 1–9, arXiv:2212.05604, Bibcode:2022AcSN....9c...1M, doi:10.2478/asn-2022-0017.
3. ^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
4. ^ Høg, E.; et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862.
5. ^ Samus, N. N.; et al. (January 2017), "General Catalogue of Variable Stars", Astronomy Reports, GCVS 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
6. Bidelman, W. P.; MacConnel, D. J. (October 1973), "The brighter stars of astrophysical interest in the southern sky", The Astronomical Journal, 78: 687, Bibcode:1973AJ.....78..687B, doi:10.1086/111475, ISSN 0004-6256.
7. ^ Gromadzki, M.; et al. (February 2007), "On the nature of the cool component of MWC 560", Astronomy and Astrophysics, 463 (2): 703–706, arXiv:astro-ph/0611815, Bibcode:2007A&A...463..703G, doi:10.1051/0004-6361:20066538.
8. ^ Marchev, V. D.; Zamanov, R. K. (February 2024), "Mass accretion rate in the jet-driving symbiotic binary MWC 560", Bulgarian Astronomical Journal, 40: 85, arXiv:2312.04208, Bibcode:2024BlgAJ..40...85M.
9. "MWC 560". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2024-12-01.
10. Merrill, Paul W.; Burwell, Cora G. (September 1933), "Catalogue and Bibliography of Stars of Classes B and A whose Spectra have Bright Hydrogen Lines", Astrophysical Journal, 78: 87, Bibcode:1933ApJ....78...87M, doi:10.1086/143490.
11. Sanduleak, N.; Stephenson, C. B. (November 1973), "Low-dispersion spectra and galactic distribution of various interesting strong-emission-line objects in the southern Milky Way", Astrophysical Journal, 185: 899–913, Bibcode:1973ApJ...185..899S, doi:10.1086/152464.
12. Bond, H. E.; et al. (March 1984), "The Extraordinary Symbiotic-Like Variable MWC 560", Bulletin of the American Astronomical Society, 16: 516, Bibcode:1984BAAS...16..516B.
13. Tomov, T. (January 1990), Marsden, B. G. (ed.), "MWC 560", IAU Circular, 4955: 1, Bibcode:1990IAUC.4955....1T.
14. Michalitsianos, A. G.; et al. (April 1991), "Observations of the Peculiar Object MWC 560 in Outburst", Astrophysical Journal, 371: 761, Bibcode:1991ApJ...371..761M, doi:10.1086/169940.
15. Tomov, T.; et al. (September 1992), "MWC 560: jets or optically thick expanding envelope?", Monthly Notices of the Royal Astronomical Society, 258: 23–35, Bibcode:1992MNRAS.258...23T, doi:10.1093/mnras/258.1.23.
16. Iijima, T. (August 2002), "MWC 560: An SS 433 type object with a white dwarf", Astronomy and Astrophysics, 391 (2): 617–623, Bibcode:2002A&A...391..617I, doi:10.1051/0004-6361:20020816.
17. Frckowiak, S. M.; et al. (2003), Corradi, R. L. M.; et al. (eds.), "Possible Pulsations of the M Giant in MWC 560", Symbiotic Stars Probing Stellar Evolution, ASP Conference Proceedings, Vol. 303. Held 27-31 May 2002 at Isaac Newton Group of Telescopes, La Palma, Spain, vol. 303, San Francisco: Astronomical Society of the Pacific, p. 120, Bibcode:2003ASPC..303..120F, ISBN 1-58381-152-4.
18. ^ Stute, M.; Sahai, R. (April 2009), "Detection of X-rays from the jet-driving symbiotic star MWC 560", Astronomy and Astrophysics, 498 (1): 209–215, arXiv:0902.1526, Bibcode:2009A&A...498..209S, doi:10.1051/0004-6361/200811176.
19. Munari, U.; et al. (November 2016), "The 2016 outburst of the unique symbiotic star MWC 560 (= V694 Mon), its long-term BVRI evolution and a marked 331 days periodicity", New Astronomy, 49: 43–49, arXiv:1607.06309, Bibcode:2016NewA...49...43M, doi:10.1016/j.newast.2016.06.004.
20. Marchev, D.; et al. (February 2023), "MWC 560 remains in high state", The Astronomer's Telegram, 15906: 1, Bibcode:2023ATel15906....1M.

Further reading

• Ando, Kazuko; et al. (December 2021), "Optical spectroscopic observations of a symbiotic star MWC 560 in the mass accumulation phase", Publications of the Astronomical Society of Japan, 73 (6): L37–L41, Bibcode:2021PASJ...73L..37A, doi:10.1093/pasj/psab104.
• Kondratyeva, L. N.; et al. (September 2021), "Active Stage of the Symbiotic Object MWC 560, 2018-2021", Astrophysics, 64 (3): 306–315, Bibcode:2021Ap.....64..306K, doi:10.1007/s10511-021-09691-2.
• Zamanov, R. K.; et al. (May 2020), "Flickering of the jet‑ejecting symbiotic star MWC 560", Astronomische Nachrichten, 341 (4): 430–440, arXiv:2004.00511, Bibcode:2020AN....341..430Z, doi:10.1002/asna.202013730.
• Leibowitz, Elia M.; Formiggini, Liliana (August 2015), "Three Fundamental Periods in an 87 Year Light Curve of the Symbiotic Star MWC 560", The Astronomical Journal, 150 (2), id. 52, arXiv:1506.05584, Bibcode:2015AJ....150...52L, doi:10.1088/0004-6256/150/2/52.
• Arrieta, A.; et al. (April 2005), "The Proto-Planetary Nebula M1-92 and the Symbiotic Star MWC 560: Two Evolutionary Phases of the Same Type of Object?", The Astrophysical Journal, 623 (1): 252–268, Bibcode:2005ApJ...623..252A, doi:10.1086/428391.
• Tomov, T.; Kolev, D. (April 1997), "Monitoring MWC560 ~ V694 Monocerotis in 1990-1995. II. Plate spectra", A & A Supplement Series, 122: 43–49, Bibcode:1997A&AS..122...43T, doi:10.1051/aas:1997326.
• Meier, Steven R.; et al. (January 1996), "Near-Infrared Spectrophotometry of the Eruptive Star MWC 560", Astronomical Journal, 111: 476, Bibcode:1996AJ....111..476M, doi:10.1086/117798.

v t e Constellation of Monoceros
List of stars in Monoceros Monoceros in Chinese astronomy Monocerotids Monoceros Ring
Stars	Bayer α β γ δ ε ζ Flamsteed 1 2 3 6 7 9 10 12 13 14 16 17 18 19 20 21 23 24 25 27 28 77 Ori 78 Ori Variable R S (15) T U V RU RW SV TU UX VV VY AO AR AU AX BE BN BT BX CL CS CV CW DD FU GI IM PZ V372 V396 V474 V505 V569 V577 V578 V582 V588 V589 V590 V592 V614 V616 V638 V640 V641 V644 V653 V682 V684 V689 V694 V695 V696 V700 V715 V721 V723 V728 V731 V739 V743 V750 V753 V827 V838 V926 HR 2150 2154 2179 2205 2224 2234 2237 2267 2270 2280 2292 2300 2313 2317 2321 2324 2325 2328 2333 2342 2347 2355 2367 2370 2375 2378 2381 2386 2395 2406 2409 2418 2426 2430 2440 2458 2461 2467 2469 2474 2479 2502 2508 2514 2521 2530 2543 2551 2555 2570 2572 2577 2582 2584 2589 2599 2606 2610 2613 2624 2627 2636 2639 2647 2655 2656 2663 2676 2694 2731 2732 2739 2752 2765 2806 2807 2811 2833 2865 2866 2867 2876 2883 2920 2958 3014 3047 3054 3072 3150 3172 3174 3189 HD 42132 44179 44219 45090 45166 45215 45652 (Lusitânia) 46149 46150 46202 46223 46375 46966 48099 50064 50138 50281 52265 (Citalá) 65938 66428 Other A0620-00 AFGL 961 CoRoT-1 CoRoT-4 CoRoT-5 CoRoT-7 CoRoT-12 CoRoT-13 CoRoT-14 CoRoT-15 CoRoT-18 CoRoT-19 CoRoT-20 CoRoT-21 CoRoT-24 Gliese 282 Monoceros R2 IRS 3 NGC 2264 IRS 1 Ross 614 Scholz's SCR 0640−0552 UGPS J0652+0324 UGPS J0722−0540
Exoplanets CoRoT-1b CoRoT-4b CoRoT-5b CoRoT-7b CoRoT-7c CoRoT-7d CoRoT-12b CoRoT-13b CoRoT-14b CoRoT-15b CoRoT-18b CoRoT-19b CoRoT-20b CoRoT-20c CoRoT-21b CoRoT-24b CoRoT-24c HD 44219 b HD 45652 b (Viriato) HD 46375 b HD 52265 b (Cayahuanca)
Star clusters	NGC 2232 2244 2264 2301 2349 2353 2506 Other Messier 50 Christmas Tree Cluster Snowflake Cluster
Nebulae	NGC 2170 2261 2264 2346 Other Cone Nebula Fox Fur Nebula IC 447 IC 2177 Red Rectangle Nebula Rosette Nebula
Galaxies	NGC 2494 Other PKS 0805-07
Category

• Cataclysmic variable stars
• Red giants
• White dwarfs
• Monoceros
• MWC objects
• Objects with variable star designations