METER-CLASS ASTRONOMY CONFERENCE
Telescopes, Instruments, and Observational Programs
International Conference January 20-22, 2012
Pre-conference tour: Volcanoes National Park - January
18, 2012
Pre-conference insider tours: Mauna Kea - January 19, 2012
Canada-France-Hawaii Telescope (CFHT) Headquarters
Waimea (near Kona), the Big Island of Hawaii
Conference Organizers
Co-chairs:
Russell Genet, California Polytechnic State University,
RussMGenet@aol.com
Bruce Holenstein, Gravic, Inc.,
BHolenstein@Gravic.com
Local Host:
Christopher Erickson, Consulting Engineer
christopher.k.erickson@gmail.com
Website
www.AltAzInitiative.org
Conference Introduction
(By conference co-chairs
Russ Genet & Bruce Holenstein)
Short Version (Detailed
Version Below) (Conference
Organizational Specifics)
This conference is devoted to a specialty branch of
astronomy—the development and use of meter-class telescopes. These telescopes trace their
origins to John Dobson and his innovative ideas for
making relatively large aperture alt-az telescopes from
low cost materials with ordinary tools. Amateur
telescope makers have continued to refine these alt-az
telescopes which, not surprisingly, have come to ever
more closely resemble their huge mountaintop cousins.
Heavy, enclosed Sonotubes have been replaced with
lightweight, open trusses. Mirrors have become thinner
and significantly larger in diameter—supported by
increasingly sophisticated whiffletrees. Computer
controlled slewing and tracking have been added.
Temperature compensated focusers and instrument rotators
facilitate long-exposure astro-imaging.
The Alt-Az Initiative was founded in June 2007 with the
express purpose of facilitating the evolution of
portable, lightweight, low cost, meter-class alt-az
telescopes. The Initiative, from its inception, aimed at
achieving much larger aperture portable telescopes than
currently existed. Initiative members quickly realized
that it would pay to closely examine the technologies
already developed for modern mountaintop telescopes, so
they initiated a purposeful “tech transfer” program that
would, at low cost, innovatively emulate appropriate
technologies such as direct drives, thin active primary
mirrors, deformable secondary mirrors, multiple mirrors,
etc.
The primary application
of portable meter-class telescopes has been, and will
likely continue to be, visual observations. Portability
allows telescopes to be safely stored at homes and
schools in light polluted cities, yet operated just
hours away under dark skies. Large apertures allow faint
objects to be observed, while low costs inable
widespread ownership and use. Thanks to
computer-controlled slewing, tracking, and instrument
rotation, portable meter-class telescopes are beginning
to be used for astro-imaging and, increasingly, in
various areas of instrumented scientific research.
Mirrors, especially low
cost, lightweight mirrors, are the key ingredient
required for the continued evolution of meter-class
portable telescopes. Active efforts are underway to
further develop meniscus, sandwich, foam glass
composite, spin cast, and layered mirrors. Forces are
just beginning to be applied to adjust the figures of
lightweight thin meniscus primary mirrors in meter-class
telescopes in a manner somewhat similar to their large
mountaintop relatives. Similarly, work has just begun on
low cost active secondary mirrors which can be “warped”
to counteract distortions in lightweight primary
mirrors. Such active mirrors can also be tip/tilted to
reduce the effects of the wind gusts on portable
telescopes. Finally—also similar to the largest
mountaintop telescopes—we anticipate that the largest
meter-class telescopes will employ multiple mirrors to
reduce weight and facilitate their manufacture and
handling.
Recreational visual astronomers are interested in
everything they have a chance to see, so the exciting
advantage of a high optical quality, one person set-up,
meter-class telescope is that there is so much more to
observe. Visual observers marvel at seeing the real
photons from objects. Some are excited by being able to
barely detect the faintest possible objects such as
distant galaxy clusters, quasars, and gravitational
arcs. Astro-imaging can also benefit from larger
apertures and portability.
Scientific research
programs, as is the case with visual and astro-imaging
programs, can benefit from larger apertures and the dark
sky opportunities that portability creates. In addition
to greater program object fluxes, scintillation noise
decreases with telescope aperture, so meter-class
telescopes have superior program object signal-to-noise
ratios for a given integration time.
There are instances where scientific observations
actually require portability. For example, the size and
shape (and hence albedos) of smaller diameter
trans-Neptunian objects (TNOs) can be determined from
occultations observations as a TNO passes in front of a
star, casting a narrow shadow that races across the
Earth. Since such narrow shadows rarely pass over fixed
location observatories, they must be observed with
portable telescopes. With larger, meter-class
telescopes, many more TNO occultations can be observed
than would otherwise be possible.
Telescopes may also
need to be moved to a location not because of some
astronomical event, but because the local observing
conditions are advantageous in some way. For example,
near infrared photometry (especially Ks band) benefits
from high altitudes and dry skies. A number of
mountaintop observatories, blessed with good roads to
the summit, would not mind sharing their skies with
portable meter-class telescopes.
The era of portable meter-class astronomy has been
underway now for several decades—ever since large
aperture alt-az Dobsonian telescopes first made their
first appearance. Visual observations through Dobs have
endeared an entire generation of the public to
observational astronomy. We hope and expect that the use
of portable meter-class telescopes will increasingly be
extended beyond visual observation, not only to
recreational astro-imaging, but also to a wide variety
of scientific research projects. The dark skies beckon
the ever increasing numbers of portable meter-class
telescopes of all types.
We maintain that portability doesn’t have to be
restricted to “smaller” apertures.
The
only limits should be our ingenuity and what can be
legally towed down the road. There is no reason we
shouldn’t see portable 2 meter telescopes in the near
future, starting first with on-axis light buckets and
then spreading to imaging telescopes. There will be many
problems to overcome on the way to 2-meter portability,
but working together we'll solve them all—one at a time.
Back to Top
Detailed Version
The
conference is devoted to a specialty branch of the
astronomy family tree—the development and use of
portable meter-class telescopes. These telescopes trace
their origins to John Dobson and his innovative ideas
for making relatively large aperture alt-az telescopes
from low cost materials with ordinary tools. These alt-az
telescopes more closely resembled their large
mountaintop alt-az brethren than other small amateur
telescopes which, at the time, were almost all of very
modest aperture and equatorially mounted.
Amateur telescope makers have continued to
refine alt-az telescopes which, not surprisingly, have
come to even more closely resemble their huge
mountaintop cousins. Heavy, enclosed Sonotubes have
been replaced with lightweight, open trusses. Mirrors
have become thinner and significantly larger in
diameter—supported by increasingly sophisticated
whiffletrees. Computer controlled slewing and tracking
have been added. Temperature compensated focusers and
instrument rotators facilitate long-exposure astro-imaging.
The Alt-Az Initiative was founded in June
2007 with the express purpose of facilitating the
evolution of portable, lightweight, low cost,
meter-class alt-az telescopes. The Initiative, from its
inception, aimed at achieving much larger aperture
portable telescope than currently existed, setting 1.5
meters as its initial goal. Initiative members
realized, from the outset, that it would pay to closely
examine the technologies already developed for modern
mountaintop telescopes, so they initiated a purposeful
“tech transfer” program that would, at low cost,
innovatively emulate appropriate technologies such as
direct drives, thin active primary mirrors, deformable
secondary mirrors, multiple mirrors, etc. Thanks to
“free” ATM labor, rapid advances in low cost
electronics, innovative engineering, sharing of
information, and rapid prototyping, Initiative members
are successfully transferring enabling technologies from
larger to smaller alt-az telescopes, thus advancing the
era of portable meter-class astronomy.
The primary application of portable
meter-class telescopes—discussed in more detail
below—has always been, and will likely continue to be,
visual observations. Portability allows telescopes to
be safely stored at homes and schools in light polluted
cities, yet operated just hours away under dark skies.
Large apertures allow faint objects to be observed,
while low costs facilitate widespread ownership and
use. Thanks to computer-controlled slewing, tracking,
and instrument rotation, portable meter-class telescopes
are beginning to be used for Astro-imaging and,
increasingly, in various areas of instrumented
scientific research.
To facilitate discussion, we have divided
portable meter-class telescopes into three basic types:
visual observation telescopes, general-purpose imaging
telescopes, and on-axis light bucket telescopes. Each
type is discussed below.
Visual
Observation Telescopes
These “eyeball at the eyepiece” telescopes require high
quality optics, and need to be easily transported and
quickly set up. They can be either “pure”
non-computerized “push Dobs,” or they can be equipped
with modest performance go-to/tracking systems. Image
rotators, generally, are an unnecessary and hence
unwanted complication.
The main use of these telescopes is recreational
observing, but they are also used for public outreach,
education, and scientific observations such as searches
for supernovae, faint visual double star astrometry, and
faint visual variable star photometry. The
recreational, public outreach, educational, and
scientific aspects of these telescopes meld together
nicely. These telescopes appeal to a wide and diverse
set of users. Think modern large aperture Dobs.
Emphasis is on 0.4 to 1.0 meter apertures, fast optical
systems, convenient portability, light weight, and
affordability.
General
Purpose Imaging Telescopes
These telescopes also require high quality optics. One
of the most important features of telescopes intended
for astro-imaging is their etendue—the product of
their aperture in square meters and their well-corrected
field in square degrees. The eye inherently senses the
total information content of an image, and it's a basic
fact of the physics of astro-imaging that the total
information content of an image (the product of the
signal-to-noise ratio and the total number of resolution
elements in the photograph) is a linear function of the
etendue of the telescope and the square root of the
exposure time. Thus, the best systems for astro-imaging
have large sensors attached to large telescopes with
high resolution, large angular fields-of-view, and
relatively short focal ratios.
To stay on target, telescopes intended for astro-imaging
require either superb long-term tracking or
autoguiding. Because they are alt-az telescopes, their
fields rotate, so accurate instrument de-rotation is
required. Operating out in the open, general purpose
imaging telescopes need to be resistant to wind gusts.
This can be achieved by designing inherently stiff
telescopes with low aerodynamic cross sections and
equipping them with fast response control systems and
rapid tip/tilt image stabilization.
These
telescopes
are not only useful for recreational astrophotography,
but also for the many science projects that utilize CCD
cameras and other sensors for astrometric, photometric,
and spectrographic observations. Everyone, scientists
included, appreciate large aperture, high resolution,
wide field-of-view, general purpose telescopes which
they can transport to their favorite dark sky site and
set up in minutes. Think the perfect portable
meter-class telescope.
As with visual telescopes, the greatest interest is
between 0.4 and 1.0 meters. Larger than this, high
performance, general purpose telescopes rapidly get
prohibitively heavy and expensive. However, for some
science applications, larger effective apertures can be
achieved by forming an array of several general purpose
imaging telescopes. Images or data can be combined
electronically or optical fibers brought together to
feed a single detector, different color bands can be
observed simultaneously, or telescopes can be spread out
in a line to “map” the shape of an asteroid. Such
arrays of general purpose imaging telescopes would be
adaptable to a wide number of uses.
For the same aperture, general purpose imaging
telescopes are necessarily more expensive than visual
telescopes, so they occupy a different niche. There are
no free lunches.
On-Axis Light
Bucket Telescopes
Light bucket telescopes are light concentrators used in
those areas of astronomical research where vast
quantities of ultra low cost, on-axis photons are
required. There is no more authoritative
definition of astronomical terms than the Cambridge
Dictionary of Astronomy (Mitton 2001). Mitton’s
definition:
Light
bucket:
a colloquial expression for a flux collector.
Flux
collector:
a
telescope designed solely to collect radiation in order to measure
its intensity or to carry out spectral analysis. No
attempt is made to form an image so a flux collector can
have a more crudely figured reflective surface than a
conventional telescope.
Light bucket telescopes are advantageous in
those situations where—compared to the noise from the
sky background—the noise from one or more other sources
is dominant. Putting it the other way around, light
bucket telescopes can be advantageous when the sky
background is a small or nearly negligible source of
noise. This situation can occur when:
(1)
the object being observed is very bright,
(2)
the integration times are very short and hence photon
arrival noise becomes important,
(3)
scintillation noise becomes a dominant noise source,
(4) the bandwidth is very
narrow or the light is spread out as in spectroscopy
resulting in significant photon arrival noise, or
(5) noise from the
detector is dominant (as it can be in the near infrared
if the on-axis diameter of the detector is significantly
larger than the seeing spot size).
The on-axis optical
performance of light bucket telescopes need not be any
better than average lowland seeing and, for many types
of observation, can be significantly worse. Since
observations are on-axis, instrument rotators are not
usually required. Furthermore, optical systems for
on-axis (or very narrow field-of-view) telescopes can be
easier to design and fabricate than for wide
field-of-view telescopes. For example, it is very
difficult, over a wide field-of-view, to correct the
spherical aberration in a telescope with a large
aperture, fast, spherical primary mirror. On axis (or
for a very narrow field-of-view) the correction is
relatively straight forward, thus not only allowing low
cost spherical primary mirrors to be utilized.
Opticians we have talked to point out that the real work
in mirror making is not obtaining a spherical
surface—the natural surface you get when you rub two
pieces of glass against each other, but in forcing the
surface to become parabolic and not revert back to being
a sphere. The faster a parabolic mirror the more
difficult it is to make, but this is not the case for
spherical mirrors. Finally, spherical mirrors have the
advantage that they can be combined together in a
multiple mirror telescope to form a much larger
spherical surface. Two of the world’s largest aperture
telescopes utilize multiple spherical mirrors—the
Hobby-Eberly and South African Large Telescope
(SALT)—utilize multiple spherical surface, hexagon
shaped mirrors to form 11 meter telescopes that were
built at a fraction of the cost of the 10 meter Keck
telescopes.
Of course there are no free lunches, and because light
buckets have, at best, narrow fields-of-view, so they
are not, essentially by definition, general purpose
telescopes. Many astronomical telescopes are
specialized. The Hobby-Eberly and SALT spherical
primary mirror telescopes mentioned above are
specialized spectroscopic telescopes. The robotic
telescopes at the Fairborn Observatory, which began
operation in 1983, were specialized for aperture
(on-axis) high-precision photometry. In these and many
other instances, the telescope itself has been optimized
for a single, dedicated function. Rather than
maximizing etendue, light bucket telescopes march to the
beat a different drummer: maximizing, for a given cost,
the number of target photons that fall within a
reasonable spot size. Think photon economics.
The "sweet" aperture range for portable light bucket
telescopes is 1 to 2 meters, with emphasis on the high
end. Arrays of 2 meter portable light bucket telescopes
would be very useful. Seven 2 meter telescopes would
have the light collecting area of a single telescope
larger than 5 meters in aperture. Such an array could
be formed into an intensity interferometer that could
image details on the surfaces of large nearby stars. It
is surprising that an array of on-axis high speed
photometric telescopes could produce an image the
largest aperture, high resolution telescopes cannot, but
several groups are pursuing the quantum effect intensity
interferometry initiated by Hanbury-Brown many decades
ago in Narrabri, Australia, when he directly measured
the diameters of many of the closest stars with a
two-telescope interferometer.
Set up time for on-axis light bucket telescopes can be
longer than other types, as this is not recreation
per se, just grunt-work observational science.
Similarly, transportation requirements can be more
demanding (e.g. sizeable but still roadable
trailers).
Portability
We hasten to clearly state at the outset
that we are all in favor of fixed-location
observatories. Many folks are fortunate to live under
dark night skies, and for them, a fixed-location
observatory in their back yard or on or near their
campus makes lots of sense. For those not so blessed,
owning or sharing a telescope at a remote, good-weather
dark site is becoming an increasingly attractive and
economically feasible possibility.
It is also worth noting that operation of
portable telescopes from a fixed-location observatory is
very common. Although the telescopes are perfectly
capable of being transported elsewhere, the owner
chooses to keep them at home except perhaps for the
occasional summer star party or a move due to job
relocation or retirement. Some of us are blessed with
exceedingly fine observing weather for months on end,
and can simply leave a portable telescope out in the
open in our yard. When the weather turns bad or we head
out for a vacation, we can simply roll our telescope
inside or take it with us.
Howard Banich’s now classic definition of
portability requires that, on arrival at the operational
location, the telescope can be extracted from its
transport vehicle and assembled by no more two persons
in a half hour or less (see Howard’s “Telescope
Portability: Moving a Big Telescope Doesn’t Have to Be
Difficult,” in The Alt-Az Initiative: Telescope,
Mirror, and Instrument Developments). Of course a
telescope can still be useful even if it doesn’t meet
Howard’s requirement, but its likelihood of frequent use
will not be as great. A related issue is the time and
effort required to align a telescope once it gets dark.
Computerized alt-az telescopes with sophisticated
alignment systems can generally be aligned much faster
than non-computerized or equatorial telescopes.
Built-in GPS and electronic
compass telemetry can shave minutes off of the alignment
process. Sidereal Technology’s control systems not only
incorporate totally automatic alignment, but mount
modeling. Plate Solve XP, written by Dave Rowe handles
Sidereal Technology’s automatic field recognition and
centering.
While it is obvious that if a telescope
requires an 18-wheeler to move, or an industrial crane
to emplace, it isn’t portable, there are various grades
of probability. We suggest, below, four such grades.
Ultra-lightweight telescopes
are designed to enable a single person to transport and
set up a sizeable aperture telescopes. Two excellent
examples of ultra lightweight telescope are those
designed and built by Mel Bartels (http://www.bbastrodesigns.com/trilateral.html)
and Greg Babcock (http://www.synrgistic.com/astro/24inch.htm).
Mel defines ultra-lightweight telescopes as telescopes
where the weight of the entire telescope sans primary
mirror is approximately one-half the weight of the
lightweight
primary mirror itself. The mirror in Mel’s
20 inch telescope weighs 50 lbs, while his entire
telescope, including the mirror, weighs only 75 lbs.
Airline check-in telescopes
can be carried as “luggage” on normal domestic or
international flights. Most airlines allow, for an
additional fee, overweight (70 lbs) and oversize (80
linear inches) bags. Both ultra-lightweight and airline
check-in telescopes should easily fit within ordinary
cars for transport.
SUV/pickup telescopes
range from fairly
lightweight telescopes easily loaded into a small SUV by
a single person in a “wheelbarrow” mode, to telescopes
which weigh many hundreds of pounds and require
mechanical assistance—such as a winch—to load. This
class of telescopes is too heavy or large to transport
on an airplane as check-in luggage or fit in a car.
Trailer telescopes,
in turn, are too
large to fit with into an SUV or even in the back of a
pickup truck, but they can be loaded on a trailer that
can be towed down the road without any special permits.
Such heavy telescopes might benefit from motorized
wheels or even being built right into the trailer
itself. If you can’t at least
tow a telescope down the road by an ordinary
vehicle without a special permit, it isn’t a portable
telescope.
Developmental Programs
Designing and building portable meter-class
telescopes can be challenging, thanks not only to
constraints on their size and weight, but also to the
demands of transportation and field assembly and
operation. A number of parallel developmental efforts
are being pursued by the members of the Alt-Az
Initiative. Their progress had been reported in the
recent book, The Alt-Az Initiative: Telescope,
Mirror, and Instrument Developments, and on their
web site
www.AltAzInitiative.org. Daily email discussions
take place at the Alt-Az Initiative’s Yahoo group.
While the technology for 0.5 to roughly 1.0
meter aperture portable telescopes that weigh a few
hundred pounds is not well established, further
development would benefit ultra-lightweight and airline
check-in telescopes. The development of technology for
portable telescopes with apertures significantly beyond
1.0 meters is only now beginning. The reasonable upper
limit to portability is probably about 2.4 meters (96
inches), the largest telescope one could transport on a
trailer without special permits. Mirrors,
especially low cost, lightweight mirrors, are the key
ingredient required for the continued evolution of
meter-class portable telescopes. Active efforts are
underway to further develop meniscus, sandwich, foam
glass composite, spin cast, and layered mirrors. Forces
are just beginning to be applied to adjust the figure of
lightweight thin meniscus primary mirrors in meter-class
telescopes in a manner somewhat similar to their large
mountaintop relatives. Similarly, work has just begun
on low cost active secondary mirrors which can be
“warped” to counteract distortions in lightweight
primary mirrors. Such active mirrors can also be
tip/tilted to reduce the effects of the wind gusts on
portable telescopes. Finally—also similar to the
largest mountaintop telescopes—we anticipate that the
largest meter-class telescopes will employ multiple
mirrors to reduce weight and facilitate manufacture and
handling.
Observational Programs
Visual Recreational, Outreach, and
Educational
observational programs involve both recreational
observing for enjoyment, as well as public outreach, and
education. Recreational visual astronomers are
interested in everything they have a chance to see, so
the exciting advantage of a high optical quality, one
person set up, one meter telescope is that there’s much
more to observe. Visual observers marvel at seeing the
real photons from objects ranging from our solar system
to billions of light years away. Many are inspired by
the excellent astro-images being made today and want to
see a similar amount of detail visually. Some are
excited by being able to barely detect the faintest
possible objects such as distant galaxy clusters,
quasars and gravitational arcs. Other examples:
-
Planetary detail in
saturated color.
-
Hints of color in the
brighter emission nebulae.
-
Spiral arms in 17th
magnitude and brighter galaxies.
-
HII regions and star
clusters in 16th magnitude and brighter
galaxies.
-
Exotic new
discoveries like Hanny’s Voorwerp.
-
Tidal distortions in
Arp peculiar galaxies.
-
Seeing colors in the
stars that make up the brighter globular clusters.
-
Seeing the complex
internal structure of planetary nebulae, their
central stars, and extended halos.
-
19th
magnitude and brighter supernovae in distant
galaxies.
-
Digging out small
scale, faint details in brighter objects like
Herbig-Haro objects in M20.
-
Soaking in the
glorious, exquisite details of brighter objects like
M51, M42, Saturn, etc…
The lowest power of a high quality one meter f/3
Newtonian that produces a 7 mm exit pupil is 150 with a
field-of-view is just under 0.6 degree using a 21mm
Ethos eyepiece and the Paracorr 2 coma corrector. This
combination is large enough to see the entire Moon and
big chunks of larger deep sky objects such as the Veil
Nebula. The field of view at lowest power should be well
corrected to the edge and provide an aesthetically
pleasing image. That’s exciting enough, but the sharp
and detailed, high power images portable meter-class
telescopes are capable of producing under a dark,
transparent, and steady sky are their real strength and
appeal. Visual observers will appreciate the
convenience of a comfortable Nasmyth focus viewing
position.
Astro-Imaging
can also benefit from larger apertures and portability. As
suggested by Dave Rowe, a 1-meter f/3 telescope with a
52 mm diameter field would be marvelous instrument for
astrophotography. The focal length is perfectly matched
to the pixel size and average seeing, and the wide field
allows for the greatest possible (affordable) etendue,
for spectacular wide-field imaging. The optics for such
a telescope are something of a challenge.
Scientific Research
programs, as is the case
with visual and astrophotography programs, can benefit
from larger apertures and the dark skies opportunities
that portability creates. In
addition to greater program object fluxes, scintillation
noise decreases with telescope aperture, so meter-class
telescopes have superior program object signal-to-noise
ratios for a given integration length.
Although the bulk of scientific observations are now
made with instruments, visual scientific observations
can still make significant contributions to the
advancement of our knowledge. Some of the visual
observations that could benefit from portable
meter-class telescopes include discovery searches for
supernovae in not-too-faint galaxies, visual photometric
observations of fainter variable stars such as Miras,
dwarf novae (to see which stars are “up”), and
astrometric measurements with laser-etched astrometric
eyepieces of fainter double stars.
There
are instances where scientific observations actually
require portability. For example, the size and
shape (and hence albedos) of smaller diameter
trans-Neptunian objects (TNOs) can be determined from
occultations observations as a TNO passes in front of a
star, casting a narrow shadow that races across the
Earth. Since such narrow shadows rarely conveniently
pass over fixed location observatories, they must be
observed with portable telescopes. With larger,
meter-class telescopes, many more TNO occultations can
be observed than would otherwise be possible.
Telescopes can be moved to a location not
because of some astronomical event, but because the
local observing conditions are advantageous in some
way. For example, near IR photometry, especially Ks
band, benefits from high altitudes and dry skies. A
number of mountaintop observatories, blessed with good
roads to the summit, wouldn’t mind sharing their skies
with portable meter-class telescopes.
Conclusions
We
have described three basic types of portable meter-class
telescopes: visual observation, general purpose imaging,
and on-axis light bucket. Each type has its own
strengths and weaknesses when it comes to the three
types of observational programs mentioned above (visual
recreational, astro-imaging, and scientific research).
Think different strokes for different folks.
If one’s sole interest is visual, eyeball to
the eyepiece, observing, then a lightweight telescope
that is easy to transport, quick to assemble, simple to
operate and maintain, and has a fast, wide
field-of-view, then a visual observation telescope will
give you the best value. No sense paying a premium
price or putting up with the complexities of high
precision tracking and instrument rotation needed for
astro-imaging. Whether your visual observations are
recreational, scientific research, or both, KISS may
apply to you. Although they are obviously specialized,
visual telescopes are currently the most numerous type
of portable meter-class telescopes and are likely to
remain so for the foreseeable future. They are leading
the way into meter-class telescopeland.
On the other hand, if one is interested in
both visual observing and astro-imaging, then a general
purpose imaging telescope may be your best choice.
These telescopes are also excellent scientific work
horses, as they can handle every sort of detector, be it
area (cameras) or point source (photodiodes,
spectrographs, etc.). Of course for the same aperture,
these telescopes are more expensive than visual
observation telescopes. They are just beginning to
appear on the market.
If one is only interested in aperture
photometry, spectroscopy, or polarimetry, then an
on-axis light bucket telescope may give you the most
on-sensor photons for your dollar. These are
specialized telescopes—they typically don’t even feature
an eyepiece! If you main interest isn’t a specialized
area of scientific research, then one of the telescopes
is probably not for you. These are relatively rare
telescopes and are likely to remain so.
The era of portable meter-class astronomy has been
underway now for several decades—ever since the first
large aperture alt-az Dobsonian telescopes first made
their appearance. Visual observations through Dobs have
endeared an entire generation of the public to
observational astronomy. We
hope and expect that
the use of portable meter-class telescopes will
increasingly be extended beyond visual observation, not
only to recreational astro-imaging, but also to a wide
variety of scientific research projects. The dark skies
beckon the ever increasing numbers
of portable meter-class telescopes of all types.
We maintain that portability doesn’t have to be
restricted to “smaller” apertures. The only limits
should be our ingenuity and what can be legally towed
down the road. There is no reason we shouldn’t see
portable 2 meter telescopes in the near future, starting
first with on-axis light buckets and then spreading to
visual and even general purpose imaging telescopes.
There will be many problems to overcome on the way to 2
meter portability, but we'll solve them all—one at a
time.
Conference Organizational Specifics
Invited
PowerPoint talks will be 20 minutes in length.
Alternatively, all attendees are welcome to display a
poster for the entire conference.
Mid-morning
breaks will be set aside for poster discussions. Written
versions of selected talks from the conference will be
combined with other contributions to the book
Portable Meter-Class Astronomy, which will be published by the
Collins Foundation Press.
Pre-conference tours are
being arranged for
Volcanoes
National Park (Wednesday January 18) and
Mauna Kea Observatories
Thursday January 19). Post conference tour to will be arranged
if there is sufficient interest. Accompanying guests will be welcome on the tours and
evening functions.
All attendees need to register. The modest registration
fee covers miscellaneous conference expenses and morning
refreshments. Local
accommodations
are reasonably
priced. The Big Island of Hawaii is ideal for a
family
vacation.
Click
here for special information for astronomer's
visiting the Big Island
For additional Information please
see:
AltAz Initiative -
http://www.AltAzInitiative.org
Canada-France-Hawaii Telescope Headquarters -
www.cfht.hawaii.edu
NASA Infrared Telescope Facility -
http://irtfweb.ifa.hawaii.edu
Gemini Telescope -
http://www.gemini.edu
Mauna Kea Visitor Information Station -
http://www.ifa.hawaii.edu/info/vis/
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