Triggers:TTau - Revision history

Chris.davis: /* FU-Ori and EX-Ori and other outbursts */

2013-07-26T15:10:05Z

FU-Ori and EX-Ori and other outbursts

Chris.davis: /* Spectral features */

2013-07-26T13:48:42Z

Spectral features

Chris.davis: /* Relevant characteristics of TTSs: */

2013-07-26T13:48:09Z

Relevant characteristics of TTSs:

Chris.davis: /* Spectral features: */

2013-07-26T13:47:53Z

Spectral features:

Chris.davis: /* FU-Ori and EX-Ori and other outbursts */

2013-07-26T13:45:23Z

FU-Ori and EX-Ori and other outbursts

Chris.davis: /* Spectral features: */

2013-07-26T13:14:52Z

Spectral features:

Chris.davis: /* T Tauri stars and other young variables and transients */

2013-07-26T13:02:20Z

T Tauri stars and other young variables and transients

Chris.davis: /* T Tauri stars and other young variables and transients */

2013-07-26T10:54:15Z

T Tauri stars and other young variables and transients

Chris.davis: /* T Tauri stars and other young variables and transients */

2013-07-26T10:53:38Z

T Tauri stars and other young variables and transients

Chris.davis: /* T Tauri stars and other young variables and transients */

2013-07-26T10:52:49Z

T Tauri stars and other young variables and transients

@@ Line 23: / Line 23: @@
 * P Cygni profiles (due to outflowing gas); inverse P Cygni in some cases
-== FU-Ori and EX-Ori and other outbursts ==
+== FU-Ori, EX-Ori and other outbursts ==
 Some young pre-main-sequence stars have exhibited quite drastic episodic variations.

@@ Line 21: / Line 21: @@
 * Strong forbidden emission lines; [OI], [SII], [NII], etc.
 * Lithium absorption
-* P Cygni profiles
+* P Cygni profiles (due to outflowing gas); inverse P Cygni in some cases
 == FU-Ori and EX-Ori and other outbursts ==

@@ Line 8: / Line 8: @@
 T Tauri stars are known to vary on periods of days, weeks, and months.  Causes include episodic accretion events, warped disk occultations, the transit of dark spots in the photosphere.
-== Relevant characteristics of TTSs: ==
+== Relevant characteristics of TTSs ==
 * irregular and quasi-periodic variations

@@ Line 16: / Line 16: @@
 * typically do not require a trigger, but watch list of T Tauris would be useful
-== Spectral features: ==
+== Spectral features ==
 * Strong Balmer emission lines

← Older revision		Revision as of 13:45, 26 July 2013
Line 38:		Line 38:
	[[File:FUori-spectra.jpeg\|450px\|left\|thumb\|FRODOspec data from the Liverpool Telescope ]]		[[File:FUori-spectra.jpeg\|450px\|left\|thumb\|FRODOspec data from the Liverpool Telescope ]]
	[[File:CTTS-spectra.jpeg\|450px\|right\|thumb\|FRODOspec data of DG Tau (red), CW Tau (blue) and HL Tau (green) ]]		[[File:CTTS-spectra.jpeg\|450px\|right\|thumb\|FRODOspec data of DG Tau (red), CW Tau (blue) and HL Tau (green) ]]
		+
		+	[[File:TTSvsFUor-spec.jpeg\|900px\|center\|thumb\|A comparison of red spectra for FU Ori and DG Tau]]

@@ Line 26: / Line 26: @@
 Below are sample optical spectra of classical T Tauri stars and two FU-ori type eruptive variables.
-[[File:FUori-spectra.jpeg|500px|left|thumb|FRODOspec data from the Liverpool Telescope ]]
+[[File:FUori-spectra.jpeg|450px|left|thumb|FRODOspec data from the Liverpool Telescope ]]
-[[File:CTTS-spectra.jpeg|500px|right|thumb|FRODOspec data of DG Tau (red), CW Tau (blue) and HL Tau (green) ]]
+[[File:CTTS-spectra.jpeg|450px|right|thumb|FRODOspec data of DG Tau (red), CW Tau (blue) and HL Tau (green) ]]

@@ Line 2: / Line 2: @@
 [[File:figure_ttau_mag.png|400px|right|thumb|T Cha - example of TTau star from the ASAS data]]
-T Tauri type stars (TTSs) are very young (<math> <10^7 </math> y), low mass (<math> <3 M^{}_\odot </math>), pre-main sequence objects [http://adsabs.harvard.edu/abs/1989A%26ARv...1..291A Appenzeller & Mundt 1989]. They are optically visible (spectral type F,G,K,M) and their spectral energy distributions possess a modest excess in the near- and mid-IR, although the slope of their SED in the IR is still negative.   Classical TTSs (Class II Young Stellar Objects) exhibit strong forbidden emission lines from ionised oxygen, sulphure, iron, etc., and they are often associated with Herbig-Haro jets; weak-lined TTSs (Class III YSOs) are essentially line-free.
+T Tauri type stars (TTSs) are very young (<math> <10^7 </math> yr), low mass (<math> <3 M^{}_\odot </math>), pre-main sequence objects [http://adsabs.harvard.edu/abs/1989A%26ARv...1..291A Appenzeller & Mundt 1989]. They are optically visible (spectral type F,G,K,M) and their spectral energy distributions possess a modest excess in the near- and mid-IR, although the slope of their SED in the IR is still negative.   Classical TTSs (Class II Young Stellar Objects) exhibit strong forbidden emission lines from ionised oxygen, sulphure, iron, etc., and they are often associated with Herbig-Haro jets; weak-lined TTSs (Class III YSOs) are essentially line-free.
-Class I YSOs possess a very strong IR excess (flat or positive spectral indices), are embedded, and are brighter in the near- and mid-IR bands. There is some statistical evidence that Class I YSOs - protostars - are the progenitors of TTSs; they are typically less abundant than Class II YSOs, are more likely to coincide with dark clouds and molecular cores, and may be much younger (<math> <100,000 </math> y).
+Class I YSOs possess a very strong IR excess (flat or positive spectral indices), are embedded, and are brighter in the near- and mid-IR bands. There is some statistical evidence that Class I YSOs - protostars - are the progenitors of TTSs; they are typically less abundant than Class II YSOs, are more likely to coincide with dark clouds and molecular cores, and may be much younger (< 100,000 yr).
 T Tauri stars are known to vary on periods of days, weeks, and months.  Causes include episodic accretion events, warped disk occultations, the transit of dark spots in the photosphere.