A survey for variable young stars with small telescopes: First results
  from HOYS-CAPS
  Variability in Young Stellar Objects (YSOs) is one of their primary
characteristics. Long-term, multi-filter, high-cadence monitoring of large YSO
samples is the key to understand the partly unusual light-curves that many of
these objects show. Here we introduce and present the first results of the
HOYS-CAPS citizen science project which aims to perform such monitoring for
nearby (d<1kpc) and young (age<10Myr) clusters and star forming regions,
visible from the northern hemisphere, with small telescopes. We have identified
and characterised 466 variable (413 confirmed young) stars in 8 young, nearby
clusters. All sources vary by at least 0.2mag in V, have been observed at least
15 times in V, R and I in the same night over a period of about 2yrs and have a
Stetson index of larger than 1. This is one of the largest samples of variable
YSOs observed over such a time-span and cadence in multiple filters. About two
thirds of our sample are classical T-Tauri stars, while the rest are objects
with depleted or transition disks. Objects characterised as bursters show by
far the highest variability. Dippers and objects whose variability is dominated
by occultations from normal interstellar dust or dust with larger grains (or
opaque material) have smaller amplitudes. We have established a hierarchical
clustering algorithm based on the light-curve properties which allows the
identification of the YSOs with the most unusual behaviour, and to group
sources with similar properties. We discuss in detail the light-curves of the
unusual objects V2492Cyg, V350Cep and 2MASSJ21383981+5708470.
