ABSTRACT: Of
all the extra-terrestrial intelligences (ETIs) with
Kepler-like systems only those in the direction of our
ecliptic know that our sun has a solar system including an
Earth-size planet in the habitable zone (HZ). Therefore, if
some fraction of ETIs try to communicate with known
Earth-size HZ planets we would be targeted by only those in
the direction of our ecliptic. SETI projects should
therefore concentrate their search on the ecliptic. The
professional project "Optical SETI" (at Harvard) targets
solar-like stars, regardless of ecliptic latitude, and is
based on the assumption that pulsed lasers will be used to
attract our attention. This web site describes an amateur
counterpart that endeavors to detect brief light flashes
confirmed to be extraterrestrial in origin by amateur
observations of target regions along the ecliptic.
BACKGROUND: SETI began at radio wavelengths in the 1960's
with an emphasis on frequencies near 1420 MHz (neutral hydrogen
line). In 1998 an Optical SETI search began at Harvard. In 2001
a second telescope nearby was used to verify simultaneity of
very brief flashes from selected stars. Photomultiplier tubes
are used to search for coincidences at nanosecond timescales. A
few interesting "hits" have been recorded, but they lack an
expected repeating pattern. Radio searches continue at Hat
Creek, CA with the Allen Telescope Array (0.5 to 11 GHz). As far
as I've been able to determine none of the radio or optical SETI
projects emphasize the ecliptic as a favored search direction,
although this has been suggested by Kilston
et al
(2008). The A-SETI project is a "poor man's" amateur attempt to
give the ecliptic its overdue attention. It must be said,
however, that without millisecond resolution any search strategy
is assuming that the transmitting civilization is more advanced
than an optimistic projection that can be envisioned today. But
hey, maybe capability that can be envisioned today is too
limiting a vision, and another 3 or 4 orders of magnitude in
pulse power is possible.
RATIONALE: Essentially all known exoplanets were
discovered using either the radial velocity (RV) method or the
transit method. RV observations have a limitation on the number
of stars that can be searched that is orders of magnitude less
favorable than for transit observations. Therefore, the number
of known solar systems discovered using transits will always be
orders of magnitude greater than the number discovered using RV.
I assume the same will be true for all ETIs. Most of the stars
that are within reach of a Kepler type observing system are in
directions of the Milky Way (note: Kepler's "range" of 3000 ly
> galaxy thickness of 1000 ly). Therefore, the best two
locations for SETI are in the directions of the intersection of
the ecliptic and the galactic plane. One of these is close to
the galactic center (best observed by SH observers in their
winter) and the other is in the opposite direction, in the
constellation Taurus (best observed by NH observers in our
winter). The Taurus intersection is the first of A-SETI's four
targets. The second target is the galactic anti-center, which
happens to be located near the first target. The third target is
a "moving target" because it is that spot along the ecliptic
that transits at local midnight. The fourth target is the
Andromeda Galaxy (where I detected a suspicious "star" in one of
a sequence of images; link below). For the Andromeda Galaxy
target we won't expect to see any stars at the location of
events because they will be too faint. For the other targets
(all in or galaxy) we may see a star at the location of the
event; it all depends on how far away it is and its absolute
magnitude. Dwarf stars (M dwarf, brown dwarf and white dwarf)
are intrinsically faint so they won't be seen in the non-event
images unless they're really close by.
OBSERVING STRATEGY: There are two modes for A-SETI
observing: 1) single observer, defocused, and 2) observer pairs,
sharp focus, coordinated in time and FOV. The single observer,
defocused mode won't be as sensitive, but it will permit any
observer to observer whenever skies are clear regardless of the
availability of a similar longitude paired observer. The purpose
for defocused observing is to easily remove any doubt that the
appearance of a star in one image is due to a star-like object
instead of a cosmic ray defect. An example of a defocused image
is at this
link. Initially
there will be two observer groups, one centered in Europe and
the other in the United States. This web page will specify the
"Current Target" so that all observers will have overlapping
FOVs for comparison of any suspicious hits. A list of volunteer
observers will be maintained at this web site to facilitate
coordinating the pairing of observations. A list of suspicious
hits will also be maintained so that those interested in
follow-up observations may target one of the suspicious hit
coordinates.
OBSERVER COORDINATORS: The European A-SETI coordinator
will be Joao Gregorio (ct1fgv at gmail dot com). The USA
coordinator will be Bruce Gary (a-seti at brucegary dot net).
I'm Bruce Gary, and I'm this web page's webmaster; I will
maintain an archive of relevant observations on this web page.
Observers are welcome to simply observe the "current target" (or
any target) any time without coordinating with others, but if
you want the option of comparing suspicious hits with others you
will want to observe the "current target" and also initiate an
e-mail coordination with other observers prior to observing. The
regional observing coordinators can be contacted for help with
specific observing questions (binning, filters, exposure times,
etc), help in finding observer partners and help with evaluating
the significance of suspicious events. Reports of any
interesting event are to be sent to your regional coordinator
(as described below).
CURRENT TARGET: Target A
Target A: 05:57:04 +23:26:20 (J2000), intersection of ecliptic
with galactic plane.
Target B: 05:45:40 +29:00:28 (J2000), galactic
anti-center.
1st priority.
Target C: 08:12:00 +30:40:00 (J2000), January's local midnight
ecliptic transit location.
Target D: 00:43:17 +41:16:42 (J2000), Andromeda Galaxy (6 'arc
ENE of M31 center)
OBSERVER LIST for USA:
Bruce Gary, Arizona (a-seti at brucegary dot net)
Joe Garlitz, Oregon (garlitzj at eoni dot com)
OBSERVER LIST for EUROPE: