Water vapor
emission in the vicinity of the star was detected in the microwave band by
D. F. Dickinson in 1973.[14] This is originating from strong
maser emission in a circumstellar gas-dust shell.[15] The flux density of these water masers is over 100
Jy.[9] The star is losing mass at a rate of 3×10−6 M☉·yr−1;[8] the equivalent of the
Sun's mass in 3.3 million years. The velocity of the spherically expanding gas is as high as 11 km/s in the water maser region, at a radius of 5 to 25
AU. In a
SiO emitting region located ~400 AU from the star, the gas velocity is 7.8 km/s.[16] This outflow appears clumpy and asymmetrical[17] with a strong temporal variation.[15]
^
abJoy, Alfred H. (November 1942), "A Survey of the Spectra and Radial Velocities of the Less Regular M-Type Variable Stars", Astrophysical Journal, 96: 344,
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1942ApJ....96..344J,
doi:10.1086/144469.
^
abYates, J. A.; et al. (2002), Mineese, Victor; Reid, Mark (eds.), "The H2O maser proper motions of RT Vir and VX Sgr", Cosmic Masers: From Proto-Stars to Black Holes, IAU Symposium, 206, San Francisco: Astronomical Society of the Pacific: 298,
Bibcode:
2002IAUS..206..298Y.
^
abcImai, H.; et al. (March 1997), "Measurement of shifts in line-of-sight velocities of stellar water masers using VLBI.", Astronomy and Astrophysics, 319: L1–L4,
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1997A&A...319L...1I.
^Pickering, E. C.; Fleming, W. P. (April 1896), "Harvard College Observatory, circular no. 6. New variable stars", Astrophysical Journal, 3: 296–302,
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1896ApJ.....3..296P,
doi:10.1086/140219.
^van der Veen, W. E. C. J.; et al. (March 1995), "The distribution of dust around Asymptotic Giant Branch stars", Astronomy and Astrophysics, 295: 445–458,
Bibcode:
1995A&A...295..445V.
^
abMendoza-Torres, J. E.; et al. (December 1997), "Evolution of H2O maser emission in the direction of the semiregular variable RT Virginis during 1985-1996", Astronomy and Astrophysics Supplement Series, 126 (2): 257–266,
Bibcode:
1997A&AS..126..257M,
doi:10.1051/aas:1997263.
^Yates, J. A.; et al. (2000), Kastner, J. H.; et al. (eds.), "Is the Outflow from RT Vir Bipolar or Rotating?", Asymmetrical Planetary Nebulae II: From Origins to Microstructures, ASP Conference Series, 199: 79,
Bibcode:
2000ASPC..199...79Y,
ISBN1-58381-026-9.
Etoka, S.; et al. (November 2001), "Monitoring of long term behaviour of OH masers in semiregular variables: R Crt, W Hya and RT Vir", Astronomy and Astrophysics, 378 (2): 522–538,
Bibcode:
2001A&A...378..522E,
doi:10.1051/0004-6361:20011184.
Lekht, E. E.; et al. (March 1999), "Dynamics of the circumstellar envelope of RT Virginis on the basis of the H2O maser monitoring", Astronomy and Astrophysics, 343: 241–250,
Bibcode:
1999A&A...343..241L.
Richards, A. M. S.; et al. (1999), Le Bertre, T.; et al. (eds.), "A MERLIN movie of mass-loss from RT Vir", Asymptotic Giant Branch Stars, IAU Symposium, 191: 315,
Bibcode:
1999IAUS..191..315R,
ISBN1-886733-90-2.