December 19, 2013: Darryl Sergison (University of Exeter) has requested AAVSO assistance with a campaign he is carrying out on five T Tauri stars. This study is the one for which AAVSO observers carried out a preliminary campaign last year (see Alert Notice 473 and Special Notice #306). The star list is revised and expanded from last year's list of targets. This campaign will run from now at least through the end of the 2013-2014 observing season.
This is part of an on-going study into the nature of pre-main-sequence low mass stars, using time series optical spectroscopy and UV-Visual-IR photometry and 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 in the study of chaotically variable young stars as they offer crucial datapoints in the light curve between observations made by professional telescopes.
Investigations include a range of phenomena with characteristic timescales of months to tens of minutes, and filtered CCD measurements in any of B, V, Ic, or Rc would be great on any of these timescales. Low cadence (nightly or twice a night) is useful, higher cadence (hourly or long time series) is better! Unfiltered is of less use due to the difficulties with system response and changing air-mass. Visual estimates ranging from monthly to twice in a night would be great. All contributing observers will be acknowledged in published papers.
Coordinates (2000) Range Mag(s) Sp.Type
BP TAU RA 04 19 15.83 Dec +29 06 26.8 10.7-13.6B R=11.6 K7
DN TAU RA 04 35 27.38 Dec +24 14 58.9 11.5-14.7p R=11.8 M0
V827 TAU RA 04 32 14.57 Dec +18 20 14.7 12.4-13.2V i=11.4 K7/M0V
V1068 TAU RA 04 16 28.10 Dec +28 07 35.7 12.60 - 13.21V R=11.8 K7V
V1264 TAU RA 03 24 25.25 Dec +02 31 01.0 12.51(0.23)V R=11.8 K4
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 BP TAU, DN TAU, V827 TAU, V1068 TAU, and V1264 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.
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