Supplement Since the draft of this book was submitted, remarkable progress has been achieved in the field of the physics of emission-line stars. In this supplement, selected papers (published mostly in 2005 and 2006) are presented with some notes focusing into two topics: fine structure of emission-line forming regions (envelope, wind, and disk) and magnetic fields of early-type stars (February, 2007). Structure of emission-line forming regions With the advancement of optical and infrared interferometry and other so- phisticated observational techniques, dimensions and internal structure of the emission-line forming regions have been markedly unveiled recently and com- pared with theoretical models. Many types of interferometer systems have been developed and used for observations. They include Very Large Telescope Interferometer (VLTI, ESO), Infrared and Optical Telescope Array (IOTA, Mt. Hopkins), Navy Prototype Optical Interferometer (NPOI, US Naval Ob- servatory), Stellar Interferometer (Sydney University), and Center for High Angular Resolution Astronomy (CHARA Array, Mt. Wilson). Coronagraphic Imaging system with Adaptive Optics (CIAO, Subaru telescope) also yields high spatially resolved infrared images of stellar envelopes. LBV and central stars of planetary nebulae Near-infrared observations with the VLTI have been carried out for Eta Cari- nae and the central star of planetary nebula CPD-56°8032 (Chesneau et al. 2006). Weigelt et al. (2006) measured different disk diameters of Eta Carinae in the continuum (4.3 mas), in HeI emission (6.5 mas), and in Bry emission (9.6 mas) in K band. Line emissions showed a larger diameter as compared to that in the continuum. Chesneau et al. (2005) also derived the sub-arcsecond structure of the Eta Carinae envelope in the narrow-band images at 3.74 and 4.05 urn. A butterfly-shaped dusty environment and a void around the cen- tral star were found. Through spectropolarimetric observations, Davies et al. (2005) found an aspheric and clumpy structure in the winds of LBVs, which is more apparent in stars of strong Hex emission. 503 504 Astrology of Emission-Line Stars Be stars Stee et al. (2005) reviewed the methods and techniques of interferometric observations of hot star disks with application to Be and B[e] stars. In the optical region, Tycner et al. (2005, 2006) carried out narrow-band Hex interferometry using NPOI and found the intensity distribution in the en- velopes for y Cas and <P Per, and a relationship between Hex emissionand lin- ear size of emission-line forming region for 11 Tau and f3 CMi. They attributed this relationship to the large optical thickness of Hex radiation. Grundstrom and Gies (2006) calculated numerical model of disks for the H« emission line, and found that the Hex disk radii as theoretically predicted are consistent with Hex interferometric observations. In the infrared spectral regions, various types of long baseline interferome- ters and interferometric array systems were used. Gies et al. (2007) in K band, Kervella and Domiciano de Souza (2006) in H, K bands, and Meilland and Stee (2006) determined the size and geometrical structure of the envelopes of some Be stars. Chesneau et al. (2005) carried out interferometric observations of the Be stars Alpha Arae in the N band at VLT, and derived the upper limits of the envelope size to be approximately 4 mas, corresponding to 14 stellar radius. The formation and dissipation of the envelopes of Be stars are considered by Meilland et al. (2006) and Rivinius (2005). Meilland et al. suggested two scenarios: one is the successive outbursts of central stars to form disks and rings, and the other is the slowly decreasing mass loss until the disks vanish. Rivinius considered the lifecycles of classical Be stars, similar to the successive outburst scenario of Meilland. If not replenished by subsequent outbursts, the ring will finally dissipate and Be stars will become B star. Mira variables Stratified structure of the circumstellar envelopes of Miras, such as the dif- ference in the radii of optical and radio photospheres and of inner dust shell, has been depicted by combined optical, infrared, and radio interferometers (Cotton et al. 2005, Whittkowiski and Boboltz 2005). Stellar diameters in the optical (Ireland and Scholz 2006, Ireland et al. 2005) and infrared (Millan- Gabet et al. 2005, Ohnaka et al. 2005) spectral regions revealed the marked dependence on the wavelength and pulsational phase of Mira stars, where we can see the effects of dust formation and pulsational shock propagation. Dy- namic models have been calculated and compared with observations (Ohnaka et al. 2006). Herbig Ae/Be stars Highly spatially resolved observations of HESs in the optical and infrared spectral regions have been carried out mostly by three groups: VLTI Supplement 505 (Benisty et al. 2005, Preibisch et al. 2006), IOTA (Millan-Gabet et al. 2006, Monnier et al. 2005, 2006), and Subaru CIAO (Tamura and Fukagawa 2005, Fujiwara et al. 2006, Fukagawa et al. 2006, Honda et al. 2005, Lin et al. 2006, Okamoto et al. 2005). Far-UV long-slit spectrograph with the HST is also used to resolve the inner cavity of a disk (Grady et al. 2005). Complicated structure of circumstellar disks of dust or molecular gases, such as central cavity, asymmetric disk, spiral arms, etc., are elucidated, along with some relationship with the H(X emission intensity. T Tau stars As in the case of HES, recent observations of the structure of accretion disks have been made in near- and mid-infrared spectral regions mainly at Mauna Kea (Subaru, Keck telescopes) and ESO (VLT). Particular attention has been paid to the imaging of the inner part of the disks. Akeson et al. (2005) con- firmed the existence of inner edge of dust disk using the Keck interferometer. Mayama et al. (2006) using the CIAO of Subaru telescope, and Duchene et al. (2005) combining Keck telescope II, resolveda complex circumstellar structure around the multiple system of T Tau. Quanz et al. (2006) and Millan-Gabet et al. (2006) observed the structure of optically thick accretion disk of FU Ori in mid-infrared band using the VLT interferometer. Magnetic fields of early-type stars It has long been supposed that early-type stars are lacking magnetic fields because of the absence of convection layers theoretically predicted. Recently, however, magnetic fields have been detected in early-type stars, particularly in Be and Herbig Ae/Be stars. Its significant effects on the structure and evolution of envelopes have become widely recognized. Be stars Neiner and Hubert (2005) reviewed the indirect and direct methods of detec- tion based on oblique rotator models. Rotational modulation of spectral lines and X-ray fluxes provide a promising method. Smith and Balona (2006) and Smith et al. (2006) suggested the existence of strong magnetic fields on the surface of Be stars by analyzing short-term variabilities in B, V bands, line emissions, and X-ray fluxes. Several theoretical models for magnetic winds and disks are proposed, generally based on the oblique rotator scheme with dipole-like magnetic fields (Brown and Cassinelli 2005, Maheswaran 2005, Ud-Doula et al. 2005). Cassinelli and Neiner (2005) presented a broad discussion on the origin and dissipation of magnetic fields in Be stars. On the origin, two possible mech- anisms were proposed: one is the dynamo action in the convection core and 506 Astrology of Emission-Line Stars its transportation to the surface and envelope, and the other is that the fossil fields remained from the initial stage of star formation. HES Detection and measurements of magnetic fields in HESs have been performed mainly at VLT, ESO, and at CFHT, Mauna Kea, using the spectropolarime- terse Hubrig et al. (2005, 2006) measured the magnetic fields for several HESs and found a large magnetic field of around 450 G for HD 139614 as the largest case among Herbig Ae stars. Yudin et al. (2006) detected Zeeman fea- tures in Call doublet and in metallic lines, whereas Yudin (2005) suggested the existence of localized magnetic fields generated during the evolution of circumstellar envelopes. Catala et al. (2007) observed the Herbig Ae starHD 190073 with the echelle spectropolarimetric device attached to the CFH Telescope, and de- tected the magnetic field in the photosphere of this star. Drouin et al. (2005) used both VLT and CFHT to detect the magnetic fields and chemical pecu- liarities in two HESs that are supposed to be the progenitors of the magnetic Ap/Bp stars. Hamaguchi et al. (2005) showed that the properties of thermal X-rays observed by the ASCA satellite are well explained by magnetic activity in the circumstellar disk of HESs. References LBV and central stars of planetary nebulae Chesneau, 0., Colliud, A., de Marco, 0., and 7 co-authors (2006). A close look into the carbon disk at the core of the planetary nebula CPD-56°8032. A. A., 455, 1009-1018. Chesneau, 0., Min, M., Herbst, T., and 15co-authors (2005). The sub-arcsecond dusty environment of Eta Carinae. A. A., 435, 1043-1061. Davies, B., Oudmaijer, T. D., and Vink, J. S. (2005). Asphericity and clumpiness in the winds of Luminous Bleu Variables. A. A., 439, 1107-1125. Weigelt, G., Petrov, R. G., Chesneau, 0., Davidson, K., and 21 co-authors (2006). VLTI-AMBER observations of Eta Carinae with high spatial resolution and spectral resolutions of 1500 and 10,009. Advances in Stellar Interferometry. Monnier, J. D., Scholler, M., and Danchi W. C. (eds.), Proc. The SPIE, Soc, Photo-Optical Instrumental Engineering. Bellington, WA, Vol. 6268. Be stars Chesneau, 0., Meilland, A., Rivinius, T., and 12 co-authors (2005). First VLTI/MIDI observations of a Be star: Alpha Arae. A. A., 435, 275-287. Supplement 507 Gies, D. R., Bagnuolo, W.