Anatoly Miroshnichenko

Current research interests and recent results

Summary of main accomplishments

A new group of early-type emission-line stars with circumstellar dust was selected and systematically studied

This group, tentatively called Be stars with warm dust, contains 19 B[e] objects with very strong H-alpha emission and near-IR excesses in combination with a steep decrease of the observed flux longward of 10 microns. This is one of only 7 groups of early-type stars with circumstellar dust (the others are Herbig Ae/Be, Vega-type, LBV, Planetary and Proto-Planetary nebulae, symbiotic, and VV Cep stars). My current explanation of the properties of the Be stars with warm dust is that they are mass-exchanging massive binariy systems at or soon after the rapid mass-transfer phase. Five such objects have been proven to be binaries (3 of them - AS 381, V669 Cep, and HD 327083 - I discovered myself), others are suspected.

Main publications:

Miroshnichenko, A.S., Levato, H., Bjorkman, K.S., Grosso, M., Manset, N., Men'shchikov, A.B., Rudy, R.J., Lynch, D.K., Mazuk, S., Venturini, C.C., Puetter, R.C., Perry, R.B. 2004. A&A, 417, 731. Properties of galactic B[e] supergiants. III. MWC 300.
Miroshnichenko, A.S., Levato, H., Bjorkman, K.S., Grosso, M., 2003. A&A, 406, 673. Properties of galactic B[e] supergiants. II. HDE 327083.
Miroshnichenko, A.S., Klochkova, V.G., Bjorkman, K.S., Panchuk, V.E. 2002. A&A, 390, 627. Properties of galactic B[e] supergiants. I. CI Cam.
Miroshnichenko, A.S., Bjorkman, K.S., Chentsov, E.L., Klochkova, V.G., Manset, N., Garcia-Lario, P., Perea Calderon, J.V., Rudy, R.J., Lynch, D.K., Wilson, J.C., Gandet, T.L., 2002. A&A, 388, 563. V669 Cep : A new binary system with a B[e] star.
Miroshnichenko, A.S., Bjorkman, K.S., Chentsov, E.L., Klochkova, V.G., Ezhkova, O.V., Gray, R.O., Garcia-Lario, P., Perea Calderon, J.V., Rudy, R.J., Lynch, D.K., Mazuk, S., Venturini, C.C., Puetter, R., 2002. A&A, 383, 171. The Luminous B[e] Binary AS 381.
Miroshnichenko, A.S., Levato, H., Bjorkman, K.S., Grosso, M., 2001. A&A,371, 600. Spectroscopy of B-type emission-line stars with compact dusty envelopes: HD 85567, Hen 3-140, and Hen 3-1398.
Miroshnichenko, A.S., Chentsov, E.L., Klochkova, V.G., Kuratov, K.S., Sheikina, T.A., Mukanov, D.B., Bjorkman, K.S., Gray, R.O., Rudy, R.J., Lynch, D.K., Mazuk, S., Puetter, R., Garcia-Lario, P., Perea, J.V., Bergner, Yu.K., 2000. A&AS, 147, 5. Spectroscopy and photometry of the emission-line B-type stars AS 78 and MWC 657
Miroshnichenko, A.S., Corporon, P., 1999. A&A, 349, 126. Revealing the nature of the B[e] star MWC 342
Miroshnichenko, A.S., 1998. In B[e] stars (Ap&SS Library, v.233). eds. Jaschek, C. and Hubert, A.M. Kluwer Academic Publishers, p.145. Photometry, polarimetry, and interferometry of B[e] stars (invited review).

New young intermediate-mass stars were discovered as a result of cross-corellation of optical and infrared large-scale surveys

Two new pre-main-sequence Herbig Ae/Be stars (MQ Cas and BD+11 829) were found cross-corellating the Galactic Catalog of Emission-Line Stars and the IRAS Point Source Catalog.
Thirty new Vega-type stars (young main-sequence stars with debris dusty disks) were found cross-corellating the SAO Astrometric Catalog and the IRAS Point and Faint Source Catalogs

Main publications:

Miroshnichenko, A.S., Gray, R.O., Vieira, S.L.A., Kuratov, K.S., Bergner, Yu.K. 1999. A&A, 347, 137. Observations of Recently Recognized Candidate Herbig Ae/Be Stars
Miroshnichenko, A.S., Mulliss, C.L., Bjorkman, K.S., Morrison, N.D., Kuratov, K.S., Wisniewski, J.P. 1999. MNRAS, 302, 612. Six intermediate-mass stars with far-infrared excess: a search for evolutionary connections

Results on pre-main-sequence intermediate-mass stars

- Infrared excesses of pre-main-sequence and main-sequence A-type stars were studied. A scenario of evolution of the circumstellar dust around young stars with masses 2-4 M_O was proposed.
- Spectral energy distributions (SED) and image sizes of Herbig Ae/Be stars in the wavelength range from near-UV to sub-mm were analysed and modeled. A two-component dust distribution model (optically-thick disks+optically-thin extended halos) was proposed (in collaboration with M.Elitzur, D.Vinkovic, Z.Ivezic).
- Periodic (3.68 yr) variations of the H-alpha line strength were discovered in the Herbig Be star HD 200775. The phenomenonwas interpreted in the framework of a binary model.

Main publications:

Vinkovic, D., Ivezic, Z., Miroshnichenko, A.S., Elitzur, M. 2003. MNRAS, 346, 1151. Disks and Halos in Pre-Main-Sequence Stars.
Miroshnichenko, A.S., Ivezic, Z., Vinkovic, D., Elitzur, M., 1999. ApJ, 520, L115. Dust emission from Herbig Ae/Be stars - evidence for disks and envelopes
Miroshnichenko, A.S., Mulliss, C.L., Bjorkman, K.S., Morrison, N.D., Glagolevskij Yu.V., Chountonov, G.A. 1998. PASP, 110, 883.High state of H-alpha emission activity of the Herbig Be star HD 200775
Miroshnichenko, A.S., Bergner, Yu.K., Kuratov, K.S., Mukanov, D.B., Shejkina, T.A., 1996. Astronomy Reports., 73, 509. Infrared excesses of A-type stars

Results on other emission-line stars

- Binary nature of a bright Be star, Pi Aquarii, was discovered through analysis of its radial velocity variations.
- Early development of the circumstellar disk of the brightest Be star, Delta Scorpii, was studied. Orbital elements of this high-eccentric binary system were significantly refined.
- A new galactic LBV candidate, MWC 314, was found and investigated.
- A new dusty A-type hypergiant, AS 314, was discovered and investigated.
- Three new classical Be stars (HR 241, HD 5839, and LSII+22 8) were discovered and studied.
- Photometric variability of several B[e] stars (MWC 342, MWC 623, MWC 657) was discovered.

Main publications:

Miroshnichenko, A.S., Bjorkman, K.S., Morrison, N.D., Wisniewski, J.P., Manset, N., Levato, H., Grosso, M., Pollmann, E., Buil, C., Knauth, D.C., 2003. A&A, 408, 305. Spectroscopy of the growing circumstellar disk in the delta Scorpii Be binary.
Bjorkman, K.S., Miroshnichenko, A.S., McDavid, D.A., Pogrosheva, T.M. 2002. ApJ, 573, 812. A study of Pi Aqr during a quasi-normal star phase: refined fundamental parameters and evidence for binarity
Miroshnichenko, A.S., Fabregat, J., Bjorkman, K.S., Knauth, D.C., Morrison, N.D., Tarasov, A.E., Reig, P., Negueruela, I., Blay, P., 2001. A&A, 377, 485. Spectroscopic observations of the Delta Scorpii binary during its recent periastron passage
Miroshnichenko, A.S., Chentsov, E.L., Klochkova, V.G. 2000. A&AS, 144, 379. Optical spectrum of a dusty A-hypergiant AS 314
Miroshnichenko, A.S., Fremat, I., Houziaux, L., Andrillat, Y., Chentsov, E.L., Klochkova, V.G. 1998. A&AS, 131, 469. High-resolution spectroscopy of the galactic candidate LBV MWC 314
Miroshnichenko, A.S., 1996. A&A, 312, 941. MWC 314 - a high-luminosity peculiar B[e] star
Bergner, Yu.K., Miroshnichenko, A.S., Yudin R.V., et al., 1995. A&AS, 112, 221. Observations of emission-line stars with IR excesses. II. Multicolor photometry of B[e] stars

Calibration of the basic stellar parameters

- A catalog of effective temperatures (Teff), angular diameters, bolometric corrections (BC), and photometric data for 302 bright stars was compiled. Empirical relationships between Teff and BC were derived.

Main publications:

Miroshnichenko, A.S., 1998. Proc. of the IAU Symp. N 189 ``Fundamental Stellar Properties: The Interaction Between Observation and Theory". (ed.) Bedding, T.R., Pub. School of Physics, University of Sydney, Australia, p.50. New photometric calibration of the visual surface brightness method

Research interests and ongoing projects

Star formation

- A survey of high-resolution spectra of Herbig Ae/Be stars is being conducted at the 6-meter Russian telescope.
- A survey of star formation regions beyond the 1 kpc circle from the Sun aiming at finding new pre-main-sequence stars is being conducted at the 3.6-meter CFHT.
- Analysis of the observational properties of Herbig Ae/Be stars is in progress.
- Photometric and spectroscopic study of newly discovered Vega-type stars

Nature and evolution of early-type emission-line stars

- A detailed study of the Be stars with warm dust (see above)
- Analysis of high-resolution spectra of classical Be stars and their binary nature
- Simultaneous optical and near-IR photometric survey of classical Be stars
- Refining the Be star catalog
- Constraining distances towards luminous emission-line stars through studies of interstellar lines and bands in the spectra of surrounding objects
- Spectroscopic studies of candidate LBVs and emission-line supergiants

Large-scale optical and IR surveys

- Cross-correlation of resent surveys (Guide Star Catalog, 2MASS, SDSS, MSX, etc.) in order to select faint objects with large IR excesses (candidates to Herbig Ae/Be, classical Be, B[e], Vega-type stars)

Numerical radiation transfer

- Further development of my existing multi-level Sobolev 2D radiation transfer code

Collaborations

K.S.Bjorkman, J.E.Bjorkman, N.D.Morrison (Ritter Observatory, Univ. of Toledo, USA)

E.L.Chentsov, V.G.Klochkova, V.E. Panchuk (Special Astrophys. Observatory, Russian Acad. of Sciences, Russia)

K.S.Kuratov, T.A.Sheikina (Fesenkov Astrophys. Institute, Kazakhstan)

A.V.Kusakin (Sternberg Astronomical Institute, Russia)

M.Elitzur, D.Vinkovic (Univ. of Kentucky, USA)

Z.Ivezic (Princeton Univ., USA)

R.O.Gray (Appalachian State Univ., USA)

M.A.Pogodin, N.G.Beskrovnaya, Yu.K.Bergner (Pulkovo Observatory, Russia)

H. Levato, M.Grosso (Complejo el Leonsito, Argentina)

J.S.Clark (Univ. of Sussex, UK)

D.A.McDavid (Univ. of Virginia, USA)

L.Houziaux (Royal Academy, Belgium)

P.Garcia-Lario, E.Verdugo, J.V.Perea-Calderon (ISO Data Center, Spain)

R.J.Rudy, D.K.Lynch, S.Mazuk (Aerospace Corp., USA)

N.Manset (CFHT, Hawaii, USA)

V.D.Krugov (Main Astronomical Observatory, Ukraine)

P.Bastien (Univ. of Montreal, Canada)

B.C.Reed (Alma College, MI, USA)

J.Fabregat (Univ. Valencia, Spain)

G.Weigelt (Max-Plank-Institute fur Radioastronomy, Germany)

T.L.Gandet (Lizard Hollow Observatory, Arizona, USA)

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Last updated 2004 August 12