RT Journal Article T1 The companion to the central mira star of the protoplanetary nebula OH 231.8+4.2 A1 Contreras, C. S. A1 Gil de Paz, Armando A1 Sahai, R. AB We present deep optical long-slit spectra of the peculiar protoplanetary nebula (PPN) OH 231.8+4.2 obtained with the 6.5 m Baade Telescope at Las Campanas Observatory (Chile). In addition to the molecular absorption bands characteristic of the M9–10 III star inside OH 231.8+4.2 (QX Pup), we identify lines of the Balmer series in absorption, which do not form in the cool atmospheres of late M-type stars. We also confirm the presence of a blue continuum excess with an intensity that is a factor ~30 larger than that expected for an M9–10 III star. Our results indicate the presence of a source hotter than QX Pup illuminating OH 231.8+4.2 that is likely a mainsequence star with spectral type A. We discuss how the formation and nebular evolution of OH 231.8+4.2 could have been affected by the presence of a binary system in its core. PB American Astronomical Society SN 0004-637X YR 2004 FD 2004-11-20 LK https://hdl.handle.net/20.500.14352/51797 UL https://hdl.handle.net/20.500.14352/51797 LA eng NO Alcolea, J., Bujarrabal, V., Sánchez Contreras, C., Neri, R., & Zweigle, J. 2001, A&A, 373, 932Balick, B., & Frank, A. 2002, ARA&A, 40, 439Bond, H. E. 2000, in ASP Conf. Ser. 199, Asymmetrical Planetary Nebulae II: From Origins to Microstructures, ed. J. H. Kastner, N. Soker, & S. Rappaport (San Francisco: ASP), 115Bujarrabal, V., Alcolea, J., Sánchez Contreras, C., & Sahai, R. 2002, A&A, 389, 271Cohen, M. 1981, PASP, 93, 288Cohen, M., Dopita, M. A., Schwartz, R. D., & Tielens, A. G. G. M. 1985, ApJ, 297, 702Corradi, R. L. M., Livio, M., Schwarz, H. E., & Munari, U. 2000, in ASP Conf. Ser. 199, Asymmetrical Planetary Nebulae II: From Origins to Microstructures, ed. J. H. Kastner, N. Soker, & S. Rappaport (San Francisco: ASP), 175de Marco, O., Bond, H. E., Harmer, D., & Fleming, A. J. 2004, ApJ, 602, L93Ferland, G. J. 1980, PASP, 92, 596Fluks, M. A., Plez, B., The, P. S., de Winter, D., Westerlund, B. E., & Steenman, H. C. 1994, A&AS, 105, 311Gómez, Y., & Rodríguez, L. F. 2001, ApJ, 557, L109Gurzadyan, G. A. 1997, The Physics and Dynamics of Planetary Nebulae (Berlin: Springer)Hartmann, L. 1998, Accretion Processes in Star Formation (Cambridge: Cambridge Univ. Press)Huggins, P. J., & Glassgold, A. E. 1982, ApJ, 252, 201Jacoby, G. H., Hunter, D. A., & Christian, C. A. 1984, ApJS, 56, 257Jura, M., & Morris, M. 1985, ApJ, 292, 487Kastner, J. H., & Weintraub, D. A. 1995, AJ, 109, 1211Kastner, J. H., Weintraub, D. A., Zuckerman, B., Becklin, E. E., McLean, I., & Gatley, I. 1992, ApJ, 398, 552Lanz, T., & Catala, C. 1992, A&A, 257, 663Mattei, J. A. 1997, J. AAVSO, 25, 57Meakin, C. A., Bieging, J. H., Latter, W. B., Hora, J. L., & Tielens, A. G. G. M. 2003, ApJ, 585, 482Morris, M. 1987, PASP, 99, 1115———. 1990, in From Miras to Planetary Nebulae: Which Path for Stellar Evolution? (Gif-sur-Yvette: Editions Frontières), 520Neri, R., Kahane, C., Lucas, R., Bujarrabal, V., & Loup, C. 1998, A&AS, 130, 1Reipurth, B. 1987, Nature, 325, 787Sahai, R., & Trauger, J. T. 1998, AJ, 116, 1357Sánchez Contreras, C., Bujarrabal, V., & Alcolea, J. 1997, A&A, 327, 689Sánchez Contreras, C., Bujarrabal, V., Miranda, L. F., & Fernández Figueroa, M. J. 2000a, A&A, 355, 1103Sánchez Contreras, C., Bujarrabal, V., Neri, R., & Alcolea, J. 2000b, A&A, 357, 651Sánchez Contreras, C., Desmurs, J. F., Bujarrabal, V., Alcolea, J., & Colomer, F. 2002, A&A, 385, L1Schwarz, H. E., Nyman, L.-A., Seaquist, E. R., & Ivison, R. J. 1995, A&A, 303, 833Shure, M., Sellgren, K., Jones, T. J., & Klebe, D. 1995, AJ, 109, 721Soker, N., & Rappaport, S. 2000, ApJ, 538, 241Turner, B. E. 1971, Astrophys. Lett., 8, 73Van Winckel, H. 2001, Ap&SS, 275, 159Wynn-Williams, C. G., Becklin, E. E., & Neugebauer, G. 1974, ApJ, 187, 473 NO © 2004. The American Astronomical Society. We are very grateful to B. F. Madore for kindly providing part of his telescope time to this project. The anonymous referee is also thanked for valuable suggestions. This work was performed at California Institute of Technology. C. S. C. and A. G. d. P. are respectively financed by NSF Grant 9981546 to Owens Valley Radio Observatory and NASA Galaxy Evolution Explorer. R. S. is partially financed for this work by NASA Long Term Space Astrophysics grant 399-20- 61-00-00 and by the Space Telescope Science Institute through proposals GO-08326.01-A and GO-09101.01-A. NO National Science Foundation (NSF) NO Owens Valley Radio Observatory NO National Aeronautics and Space Administration (NASA) NO NASA Long Term Space Astrophysics Program NO Space Telescope Science Institute DS Docta Complutense RD 27 abr 2024