AAVSO Alert Notice 473


T Tauri stars observing campaign

November 6, 2012


Darryl Sergison (University of Exeter) has requested AAVSO

assistance with a campaign he is organizing on six T Tauri stars.

He writes: "In Autumn 2013 I [and my PhD supervisor Tim Naylor of

Exeter University are] undertaking a new study into the nature of

pre-main-sequence low mass stars, using time series optical

spectroscopy and UV-Visual-IR photometry...to build a clearer

picture of the environment around young solar-type stars and

characterise their various disc, accretion, and outflow structures.


"This study offers a great opportunity for professional-amateur

collaboration as the objects (with V magnitudes of 10 - 13) are

well within the reach of photometry by small telescopes. Amateur

observations are uniquely useful to us in the study of chaotically

variable young stars as they offer crucial datapoints in the

lightcurve between observations made by professional telescopes.


"We would be very keen to recruit(!) AAVSO observers who are

interested in being part of this study and able to contribute

visual or (V and Rc band) filtered CCD photometry. All contributing

observers will be acknowledged in the published papers, significant

contributors may also be co-authors. I do have one spare 1.25"

V band filter that I could lend to any interested observer who may

wish to borrow it for the duration of this programme. [If you are

interested in borrowing it please email eowaagen@aavso.org].     


***"In preparation for the main data collection next autumn, we would

like to start monitoring targets immediately. The first 3 targets

that we will be studying are RY Tau, DN Tau, and DR Tau [the other

3 targets will be announced later]... ***


"As far as observations go, almost anything is useful. We are

hoping to investigate periodicity for a range of phenomena on

timescales of months to hours, so visual estimates ranging from

monthly to twice in a night would be great.


"Filtered CCD measurements in any of B, V, Ic, or Rc would be

great, again low cadence is useful, higher cadence (hourly or

long time series) is better! Unfiltered is probably of less use

to us due to the difficulties with system response and changing



"Spectroscopy would be very welcome, particularly around H-alpha

(6563A) if the resolution is greater than a few thousand.

Alternatively, low resolution right across the optical would be

great (for example with a diffraction grating in the converging

beam), particularly if a nearby main sequence star of similar

spectral type can be captured at a similar time and air-mass so

that we can characterise the system and atmosphere response at

the time of the observation."


Coordinates (2000) and Range and B-V:

RY Tau  RA 04 21 57.41 Dec +28 26 35.6   9.3-13.0 p   1.0

DN Tau  RA 04 35 27.38 Dec +24 14 58.9  11.5-14.7 p   1.4

DR Tau  RA 04 47 06.22 Dec +16 58 42.8  10.5-16 B     1.2


Charts for these stars may be created using the AAVSO Variable

Star Plotter (www.aavso.org/vsp). Photometrists should use the

photometry table provided in VSP for each star.


Please report all observations to the AAVSO International Database

using the names RY TAU, DN TAU, and DR TAU, respectively.


This campaign is being followed on the AAVSO Observing Campaigns

page (www.aavso.org/observing-campaigns).



This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.



AAVSO Special Notice #306

Telluric standards for T Tau stars campaign spectroscopists
November 7, 2012

Further to AAVSO Alert Notice 473 (www.aavso.org/aavso-alert-notice/473),
Principal Investigator Darryl Sergison (University of Exeter) requests that
spectroscopists planning to observe the targets RY Tau, DN Tau, and/or DR
Tau image the corresponding telluric standards below at the same time:

Telluric standard for RY Tau
HD 283567 B9 Vmag = 10.38 04 20 33.072 +28 39 08.55

Telluric standard for DN Tau
HD 284571 A0 Vmag = 9.71 04 37 46.253 +24 02 45.93

Telluric standard for DR Tau
HD 286036 A0 Vmag = 10.54 04 46 26.684 +15 59 45.47

Imaging these objects at the same time as the targets will enable the
removal of the effects of system response and atmospheric absorption.

Coordinates (2000)
RY Tau RA 04 21 57.41 Dec +28 26 35.6
DN Tau RA 04 35 27.38 Dec +24 14 58.9
DR Tau RA 04 47 06.22 Dec +16 58 42.8

Many thanks and good observing!

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.