Gaia Science Alerts Working Group - User contributions [en]

Triggers:TTau

2009-10-28T19:37:47Z

Pilecki:

== T Tauri stars ==
[[File:figure_ttau_mag.png|400px|right|thumb|T Cha - example of TTau star from the ASAS data]]

T Tauri type stars 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].

Characteristics:
* irregular and quasi-periodic variations
* high amplitude (up to 5 mag)
* may have a phase of quiescence (see figure)
* absolute magnitude range: M_V=? to ? mag
* ? < V-I < ?

Triggers:FUOri

2009-10-28T16:39:12Z

Pilecki:

== FU Orionis (FUors) ==
FU Orionis (V1647 Ori) is young pre-main sequence stars, illuminating a McNeil's nebula in the vicinity of NGC 2068 star-forming region.

[[File:FUOri.png]]
Plot from [http://www.ta3.sk/caosp/Eedition/FullTexts/vol36no3/pp149-157.pdf D.Chochol et al. 2006].

Characteristics:

* Very rare
* Outbursts repeat with a time scale of 40 years (1978, 2003)
* Amplitude: 5 mag over 4 months
* Outbursts last for 2 years
* Spectra: F or G supergiants
* Spectrum: red, heavily veiled continuum with strong emission of <math>H_{\alpha}</math>; in blue consistent with an early B spectral type
* X-ray variability present
* FU Ori and V1057 Cyg rise over 1 yr, whereas V1515 Cyg rise over 20 years
* FU Ori and V1515 Cyg decline over 20-100 years, V1015 Cyg decays faster (10 yrs)

== Similar types to FU Ori ==
=== EX Lupis (EXors) ===

[[File:ExLupi.png|right|400px|thumb|EX Lupi photometry from the ASAS project.]]

See Herbig (2007) [http://www.iop.org/EJ/article/1538-3881/133/6/2679/205809.text.html]

* Recurent eruptions
* Amplitudes similar or smaller than in FUors
* Balmer emission lines, He I and other lines as in active T Tauri stars

=== OO Serpentis ===
OO Ser was discovered in 1994 and is similar to FUors and EXors, but is so deeply embedded, that at its brightest was not visible in J band ([http://ukads.nottingham.ac.uk/abs/1996ApJ...468..861H Hodapp et al. 1996]).
It was observed in infrared with ''Infrared Space Observatory'' and Spitzer ([http://arxiv.org/abs/0705.1231 Kospal et al. 2007]).
It has different time scales than FUors and EXors, is rather a ''fast'' FUor (similar to V1647 Ori) with a time of rise of about 8 months.

File:ExLupi.png

2009-10-28T16:37:46Z

Pilecki: uploaded a new version of "File:ExLupi.png"

Triggers:TTau

2009-10-26T02:07:01Z

Pilecki:

== T Tauri stars ==
[[File:figure_ttau_mag.png|400px|right|thumb|Example of TTau star from the ASAS data]]

T Tauri type stars 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].

Characteristics:
* irregular and quasi-periodic variations
* high amplitude (up to 5 mag)
* may have a phase of quiescence (see figure)
* absolute magnitude range: M_V=? to ? mag
* ? < V-I < ?

File:Figure ttau mag.png

2009-10-25T22:25:51Z

Pilecki:

Triggers:TTau

2009-10-23T18:12:09Z

Pilecki: Created page with '== T Tauri stars == Example of TTau star from the ASAS data Short description. Characteristics: * irregular variations * high amp...'

== T Tauri stars ==
[[File:figure_ttau_mag.png|300px|right|thumb|Example of TTau star from the ASAS data]]

Short description.

Characteristics:
* irregular variations
* high amplitude
* may have a phase of quiescence (see figure)
* absolute magnitude range: M_V=? to ? mag
* ? < V-I < ?

Triggers

2009-10-23T18:03:35Z

Pilecki:

''' Please expand this section with your favourite types of possible alerts. The most useful information would be the number statistics, amplitude and timescale, example light curve, spectrum and the reasoning for an rapid alert.'''

===Possible triggers for Science Alerts===

* [[Triggers:Supernovae | Supernovae]]

* [[Triggers:GRBs | Gamma Ray Bursts Optical Counterparts]]

* [[Triggers:LBVs | Luminous Blue Variables]]

* [[Triggers:CNe | Classical novae]]

* [[Triggers:DNe | Dwarf novae]]

* [[Triggers:Microlensing | Microlensing events]]

* [[Triggers:Flares | M-dwarf flares]]

* [[Triggers:RCrB | R Coronae Borealis type variables (dimming objects)]]

* [[Triggers:CVs | Cataclysmic Variables (CVs)]]

* [[Triggers:FUOri | FU Orionis-type eruptive stars]]

* [[Triggers:TTau | T Tauri type pre-main sequence stars]]

* [[Triggers:Other | Other rare transients]]

== Table of transients ==
This table is based on [http://arxiv.org/abs/0906.5355 Rau et al. 2009] on Palomar Transient Factory (PTF).
MR is an absolute magnitude in R, tau is time of a decline by 2 mag.
Note, these are not all the types of transites Gaia will detect.

{| border="1" cellspacing="0" cellpadding="5" align="center"
! Class
! MR
! tau
! Universal rate
! Gaia rate
|-
| Dwarf Novae
| 9..4
| 3..20
| <math>3\times10^{-5} \textrm{pc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|Classical Novae
| -5..-10
|2..100
|<math>2\times10^{-10} \textrm{yr}^{-1}\textrm{L}_{\odot,K}^{-1}</math>
|
|-
|Luminous Red Novae
| -10..-14
|20..60
|<math>1.5\times10^{-13} \textrm{yr}^{-1}\textrm{L}_{\odot,K}^{-1}</math>
|
|-
|Fallback SNe
| -4..-21
|0.5..2
|<math>10^{-13} \textrm{yr}^{-1}\textrm{L}_{\odot,K}^{-1}</math>
|
|-
|Macronovae
| -13..-15
|0.3..3
|<math>10^{-4..-8} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|SN .Ia
| -15..-17
|2..5
|<math>(4..10)\times 10^{-6} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|SNe Ia
| -17..-19.5
|30..70
|<math>3\times 10^{-5} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|Tidal disruption flares
| -15..-19
|30..350
|<math>10^{-6} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|Core-collapse SNe
| -14..-21
|20..300
|<math>5\times 10^{-5} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|Luminous SNe
| -19..-23
|50..400
|<math>10^{-7} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|Orphan afterglows (SGRB)
| -14..-18
|5..15
|<math>3\times 10^{-7..-9} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|Orphan afterglows (LGRB)
| -22..-26
|2..15
|<math>3\times 10^{-7..-9} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|On-axis LGRB afterglows
| ..-37
|1..15
|<math>4\times 10^{-10} \textrm{Mpc}^{-3} \textrm{yr}^{-1}</math>
|
|-
|}

----
== CMD of selected variables and transients ==
CMD paths of various types of variable stars, including Be stars, R CrB and V4334 Sgr. From [http://arxiv.org/abs/0907.4090 Spano et al. 2009]

[[File:VariablesPathsCMDLMC.png|650px]]

----
== Time scales and amplitudes ==
[[File:Kulkarni-absmag-timescale.png|400px|left|thumb|Absolute magnitude vs timescale of novae, supernovae and some of new transients. From Kulkarni (2009).]]

[[File:plot_transients_tau_ampl.png|400px]]
[[File:plot_transients_trise_ampl.png|400px]]
[[File:plot_transients_tdecline_ampl.png|400px]]
[[File:plot_transients_trise_tdecline.png|400px]]