scholarly journals Oh Observations Near the Reflection Nebulae Ngc 2068 and Ngc 2071

1974 ◽  
Vol 60 ◽  
pp. 301-302
Author(s):  
L. E. B. Johansson ◽  
B. Höglund ◽  
A. Winnberg ◽  
Nguyen-Q-Rieu ◽  
W. M. Goss
Keyword(s):  
Dust Cloud ◽  
T Tauri Stars ◽  
Emission Lines ◽  
Class I ◽  
Reflection Nebula ◽  
Cosmic Background ◽  
T Tauri ◽  
Reflection Nebulae

Narrow OH emission lines at 1667 MHz, apparently from a Class I source, have been observed near the reflection nebula NGC 2071. The region contains many T Tauri stars. OH emission corresponding to the dust cloud north and east of NGC 2024 is also seen. At 1720 MHz the dust cloud component appears in absorption; presumably the isotropic 2.7 K cosmic background is being absorbed.

Two New T Tauri stars and a Candidate FU Orionis Star associated with Bok Globules

1997 ◽  
Vol 163 ◽  
pp. 839-839
Author(s):  
J. L. Yun ◽  
M. Moreira
Keyword(s):  
Infrared Emission ◽  
T Tauri Stars ◽  
Emission Lines ◽  
Young Stellar Objects ◽  
Spectral Energy ◽  
Energy Distributions ◽  
Stellar Objects ◽  
T Tauri ◽  
Bok Globules ◽  
Reflection Nebulae

AbstractWe present photometric and spectroscopic evidence of two new T Tauri stars formed in the conditions of isolated small Bok globules. The spectral energy distributions of these objects display excess infrared emission, they are associated with optical reflection nebulae, and their optical spectra reveal Balmer emission lines and the Li I λ6707 Å absorption line. Additionnally, we report the discovery of what is likely to be a new FU Orionis star seen towards Bok globule CB34. The star is about 4 magnitudes brighter than it appears on the Palomar plates and is associated with the aggregate of young stellar objects forming in Bok globule CB34.

scholarly journals Quasicyclic Light Changes in Three Low Mass T Tauri Stars

1977 ◽  
Vol 42 ◽  
pp. 66-71
Author(s):  
H. Mauder
Keyword(s):  
Variable Stars ◽  
T Tauri Stars ◽  
Emission Lines ◽  
T Tauri ◽  
Cyclic Variations ◽  
Low Mass ◽  
Photographic Survey ◽  
Objective Prism

During a photographic survey of the Chamaeleon T association in 1971/1972, evidence was found for quasiperiodic light changes of three variable stars, see Mauder and Sosna (1975). The period of 6.2 days for SY Cha is well seen, the periods of 7 days for VZ Cha and of 8 days for TW Cha are less pronounced. Intrinsic variations are present in addition to the cyclic variations. The three stars were classified by Hoffmeister (1963) as T Tauri type stars from their light variations. Objective prism spectra obtained by Henize and Mendoza (1973) confirm this classification, they found conspicuous emission lines. For SY Cha and TW Cha they got slit spectra, too, which show the typical veiling. The stars SY Cha, TW Cha and VZ Cha have been observed in the UBV system from 1974 March 12 until 1974 March 22, using the ESO standard photometer. In Figures 1 - 3 the light and colour curves are given for SY Cha, TH Cha and VZ Cha. Each point is a mean of generally 8 to 12 integrations, each integration lasting 5 seconds.

scholarly journals Stellar wind flows in T Tauri stars

1987 ◽  
Vol 122 ◽  
pp. 105-106
Author(s):  
C. Sá ◽  
M.T.V.T. Lago ◽  
M.V. Penston
Keyword(s):  
Stellar Wind ◽  
General Pattern ◽  
T Tauri Stars ◽  
Emission Lines ◽  
High Dispersion ◽  
T Tauri ◽  
Wind Flows ◽  
Using Data

Following the successful modelling of the wind from RU Lupi using data at moderate and high dispersion we report on similar observations of other T Tauri stars where the general pattern of the wind, as deduced from the widths of the emission lines of the various species, seems to be similar.

scholarly journals High Quality Echelle Observations of T Tauri Stars

1988 ◽  
Vol 132 ◽  
pp. 99-104
Author(s):  
G. Basri
Keyword(s):  
High Resolution ◽  
Line Profile ◽  
T Tauri Stars ◽  
Young Stars ◽  
Emission Lines ◽  
Current Understanding ◽  
General Nature ◽  
High Quality ◽  
T Tauri ◽  
Made In

This is a very brief review of the high resolution line profile work that has been done on very young stars. The spectral anamolies peculiar to these stars are mentioned, with some discussion of what may give rise to them. The Hα line is discussed most extensively, as the most work has been done with it. While progress has been made in understanding the general nature of T Tauri spectra, there are very large gaps in our current understanding of the emission lines from these stars.

Magnetospheric Accretion Models for the Hydrogen Emission Lines of T Tauri Stars

1998 ◽  
Vol 492 (2) ◽  
pp. 743-753 ◽  
Author(s):  
James Muzerolle ◽  
Nuria Calvet ◽  
Lee Hartmann
Keyword(s):  
T Tauri Stars ◽  
Emission Lines ◽  
Hydrogen Emission ◽  
T Tauri ◽  
Hydrogen Emission Lines ◽  
Magnetospheric Accretion

Recent Results on Associations: Anatomy of CMa OB1 and Mon OB1

1980 ◽  
Vol 85 ◽  
pp. 33-49 ◽  
Author(s):  
William Herbst
Keyword(s):  
Molecular Clouds ◽  
Line Emission ◽  
T Tauri Stars ◽  
Molecular Line ◽  
Dark Clouds ◽  
T Tauri ◽  
Sky Survey ◽  
Objective Prism ◽  
Cloud Complex ◽  
Reflection Nebulae

Three types of associations are presently recognized. These are OB, R, and T, and represent, respectively, concentrations of O and B type stars, reflection nebulae, and T Tauri stars, in certain regions of the sky. OB and T associations are identified on objective prism plates; R associations may be found using direct plates such as those of the Palomar Sky Survey. All associations are intimately connected with what appear optically as dark clouds and are now detected as sources of molecular line emission and known as molecular clouds. Often, all three types of associations are found within the same cloud complex (eg, Mon OB1). However, there are also examples of T associations (Taurus) and R associations (Mon R2) which are not connected with recognized OB associations.

scholarly journals A Comparative Study of Lithium Abundances, Radial Velocities, and Emission Lines in Pre-Main Sequence Visual Binaries

1992 ◽  
Vol 135 ◽  
pp. 63-65
Author(s):  
Eduardo L. Martín ◽  
Rafael Rebolo ◽  
Antonio Magazzù
Keyword(s):  
High Resolution ◽  
Comparative Study ◽  
Spectral Properties ◽  
Main Sequence ◽  
Angular Separation ◽  
T Tauri Stars ◽  
Radial Velocities ◽  
Emission Lines ◽  
T Tauri ◽  
First Results

AbstractHigh resolution (R ~ 20000) spectroscopic observations of visual pairs of T Tauri stars (TTS) in the spectral range 655-675 nm, and 385-405 nm for some systems, are reported. Good seeing allows us to resolve pairs with minimum angular separation of ~ 2″. The radial velocities, overall spectral properties and detection of the Li I line are used to decide whether the components of the binaries are likely to be gravitationally bounded. In this paper we present first results on a subset of our sample: 3 visual companions are not TTS, namely DL Tau/c, GG Tau/c(SW) and NTTS 45251+3016/c. The star GG Tau/c(S) is confirmed as a T Tauri star. The system UZ Tau is probably composed of at least 4 components. The star 1E0255.3+2018 (Fleming et al. 1989), previously thought to be single, is found to be a close visual binary. Finally, lithium abundances for the PMS components of 6 binaries are presented and their consistency with theoretical expectations is briefly discussed.

Observations of T Tauri Stars usingHubble Space TelescopeGHRS. I. Far‐Ultraviolet Emission Lines

2002 ◽  
Vol 566 (2) ◽  
pp. 1100-1123 ◽  
Author(s):  
David R. Ardila ◽  
Gibor Basri ◽  
Frederick M. Walter ◽  
Jeff A. Valenti ◽  
Christopher M. Johns‐Krull
Keyword(s):  
T Tauri Stars ◽  
Emission Lines ◽  
Ultraviolet Emission ◽  
T Tauri ◽  
Far Ultraviolet
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