Report - School of Physics

engage in such activity. Very recently, a dedicated campaign to observe possible
transits of GJ 876b in the system IL Aqr was announced spanning a ten-hour period
starting 21 Oct 2004 (http://www.aavso.org/news/ilaqr.shtml). ESO and ESA
could take a leading role here by establishing and coordinating a dedicated Amateur
Transit Network, an interesting opportunity for scientific reasons as well as for its
potential for public outreach.
Scientifically, the most attractive aspect is that a global network (10–20 individual
observatories) could provide very significant amounts of observing time and excellent
time coverage. The latter is also essential for finding planetary signatures in
microlensing events. Such a network probably will be the most cost-effective and
efficient way to achieve a large increase in follow-up observations of candidates. The
major challenge is to ensure that observations from different sources can successfully
be combined for analysis. To achieve the required homogeneity, ESO/ESA
could consider the use of common hardware (CCD and filters) by the members of
the network and possibly software support. Relatively modest expenditures would
be required to equip each participating observatory with a high-quality photometric
system, very beneficial in terms of data quality. Although the effort required to
coordinate such a network should not be underestimated, if properly coordinated
and supported, an ESO/ESA amateur transit network could provide a cost-effective
way to substantially increase the capablility for follow-up observations of candidates.
Such an increase seems necessary in order to keep up with the demand projected to
materialise over the next decade.
Sky & Telescope (December 2004, p18) reported that only eight days after the
transiting system TrES–1 had been announced, a transit was observed by a Belgian
amateur as well as by two observers from Slovenia. The first transit system
HD 209458 is fairly bright at V = 7.6 mag, but TrES–1 is only 11.8 mag. The
detector hardware used for the discovery of TrES–1 is quite comparable to what
advanced amateurs have. One main difference is the software which enables the
monitoring of thousands of stars, and therefore acceptable chances for discovery. In
this context, one aspect of Section 2.1.2 is recalled: Holman & Murray (2005) and
Agol et al. (2005) describe how repeated observations of transits may lead to the
discovery of Earth-mass planets: the gravitational influence of the small planet will
induce pertubations in the orbit of the much larger planet causing the transit; over
a period of time this will lead to a shift of the observed transit times on the order
of minutes. The effect is more pronounced for long-period massive planets, with
low-mass companions in orbital resonance.
Involvement of amateurs in extra-solar planet research also opens a very attractive
field in terms of public outreach and eduction. The general public clearly is very
interested in the topic of extra-solar planets. The subject therefore is well suited to
provide information and eductational material explaining the prospects and limitations
of searches for extra-solar planets to the public and decision makers. Given
the very substantial investments required to realise the next generation of extremely
large telescopes, astronomy should make a dedicated effort to take advantage of this
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