Sky & Telescope - March 2019 - 59

of the Sun. The prominence versions
(SS60P and SS80P) use a wider 0.8- to
0.6-angstrom bandpass, which displays
prominences a bit brighter than the
chromosphere model does, though at
the expense of other details across the
Sun's disk. I tested the SS60C.
The Solar Scout is a nearly complete
observing kit that incorporates a removable Quark ﬁlter - a Fabry-Pérot etalon
Hα ﬁlter that was reviewed in the
November 2014 issue, p. 38. The scope
comes with a waterproof, foam-lined
hard case, a solar "bullet" ﬁnder, an
AC-to-DC power supply, and a mounting foot threaded for ¼-20 standard
tripods that also doubles as a short
Vixen-style dovetail plate.
Optics in the SS60C are an f/3.75
doublet objective in a carbon-ﬁber
OTA, which, when combined with an
integral Barlow lens within the Quark
ﬁlter, extends the effective focal length
of the system to approximately 930mm (f/15.5) in a 16-inch-long package. Users will need to provide a star
diagonal and eyepiece. The scope's focus
travel is sufﬁcient to accommodate
most standard 1¼-inch diagonals combined with a range of eyepieces.
One useful aspect of the SS60C is
that its Quark ﬁlter is removable (an
option not available on the SS60-ds),
and, with the addition of an optional
adapter and appropriate energy-rejection ﬁlter, it can be used safely on other
refractors. This is particularly helpful
for users hoping to image the Sun, as
I'll explain later.
The Quark is a temperature-regulated Hα solar etalon that's powered by
a supplied wall transformer with a generous 9½-foot cable, which plugs into a
USB-micro port on the side of the ﬁlter.
Plug adapters are included for other
types of international wall outlets. This
power heats the Quark's etalon cavity
to between 100° and 150°F, precisely
regulating the ﬁlter's passband.
As an electrically stabilized ﬁlter,
the Quark needs to be powered up for
about 10 minutes before an observing
session begins in order for its temperature to stabilize. An LED located near
the power port changes from yellow to

green when it's ready. The LED is tiny
but bright enough to be seen in full
sunlight. While it isn't dangerous to
view through the ﬁlter while it is reaching operating temperature, the views
are extremely low-contrast and offband before stabilizing, appearing like a
white-light view, except colored red.
The power transformer provides 5
VDC at 2 amps. The Quark can also be
powered with most DC power supplies
that have a USB output, though you'll
need to ensure the power supply can
output 2 amps.
An included 14-page manual is
extremely helpful and directly answered
any questions I had whether I was using
the instrument visually or with an
imaging setup.

changing one click-stop, but contrast
improved slightly when moving several
stops at a time. The manual states that
turning the knob clockwise increases
(redshifts) the center wavelength of the
ﬁlter, while counter-clockwise decreases
(blueshifts) its central passband. This
is useful when looking at prominences
along the limb, which can sometimes
be blue- or red-shifted, revealing details
that were fainter or even invisible before
changing the ﬁlters' tuning.
Unlike a white-light view of the Sun,
observing in the dimmer, deep-red Hα

Under the Sun
Although the ﬁltering system that isolates the Hα band does permit viewing
and imaging of solar features, the quality of the view with the SS60C depends
on several factors.
The seeing or steadiness of our
atmosphere is one big consideration.
Daytime seeing is generally much worse
than nighttime and can blur ﬁne detail
associated with active solar regions.
Local conditions signiﬁcantly help or
worsen the quality of the image viewed
through any solar telescope. My best
seeing almost always came in the early
morning hours, even though the Sun
was lower in the sky than when at its
midday position. I experienced slightly
better seeing when I used the SS60C
outside on my lawn, rather than attaching the scope piggyback on my observatory telescope in its domed building.
Users can loosen a thumbscrew on
top of the scope to allow the ﬁlter to be
rotated to place the power input and
tuning knob in a convenient position.
The tuning knob has 5 click-stops
on either side of a center position, with
each click changing the transmitted
wavelength by 0.1 Å. When adjusting the knob, even slightly, the LED
changes from green back to yellow. It
takes several minutes to stabilize and
turn green again after each adjustment.
I couldn't see much difference when

pp Placing the Sun in the telescope's field
of view is easy using the bullet finder. Focusing the SS60C is accomplished by turning the
large, red anodized collar.
p The SS60C's peak passband can be adjusted +/- 0.5 angstroms in 0.1-Å increments using
the tuning knob. While most features across
the solar disk looked best at the mid-position,
prominences sometimes changed appearance
when turning the knob 2 or 3 clicks. It took
several minutes for the filter to stabilize each
time the knob was adjusted.
sk yandtele scope.com * M A RCH 2 019

http://www.skyandtelescope.com

Sky & Telescope - March 2019

Table of Contents for the Digital Edition of Sky & Telescope - March 2019