Australian Sky & Telescope - 04.2019

http://www.skyandtelescope.com.au 67

OpticsintheSS60Careanf/3.75
doubletobjectiveinacarbon-fiberOTA,
which, when combined with an integral
Barlow lens within the Quark filter,
extends the effective focal length of
thesystemtoapproximately930mm
(f/15.5)ina40-cm-longpackage.Users
will need to provide a star diagonal
andeyepiece.Thescope’sfocustravel
issufficienttoaccommodatemost
standard 1¼-inch diagonals combined
witharangeofeyepieces.
OneusefulaspectoftheSS60Cis
thatitsQuarkfilterisremovable(an
optionnotavailableontheSS60-ds),
and,withtheadditionofanoptional
adapterandappropriateenergy-
rejectionfilter,itcanbeusedsafelyon
other refractors. This is particularly
helpfulforusershopingtoimagethe
Sun, as I’ll explain later.
TheQuarkisatemperature-
regulated Hαsolar etalon that’s
poweredbyasuppliedwalltransformer
withagenerous2.9-metrecable,which
plugsintoaUSB-microportontheside
ofthefilter.Plugadaptersareincluded
fordifferenttypesofinternationalwall
outlets. This power heats the Quark’s
etalon cavity to between 38° and 65°C,
preciselyregulatingthefilter’spassband.
As an electrically stabilised filter, the
Quarkneedstobepoweredupforabout
10minutesbeforeanobservingsession
begins in order for its temperature to
steady.AnLEDlocatednearthepower

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 off-band

before stabilising, appearing like a

white-light view, except coloured 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

output2amps.

Anincluded14-pagemanualis

extremelyhelpfulanddirectlyanswered

anyquestionsIhadwhetherIwasusing

theinstrumentvisuallyorwithan

imaging setup.

Under the Sun

Although the filtering system that

isolates the Hαband does permit

viewingandimagingofsolarfeatures,

thequalityoftheviewwiththeSS60C

depends on several factors.

The seeing or steadiness of our

atmosphere is one big consideration.

Daytimeseeingisgenerallymuch

worsethannighttimeandcanblur

finedetailassociatedwithactivesolar

regions. Local conditions significantly

help or worsen the quality of the image

viewedthroughanysolartelescope.My

best seeing almost always came in the

early morning hours, even though the

Sunwaslowerintheskythanwhen

atitsmiddayposition.Iexperienced

slightly better seeing when I used the

SS60Coutsideonmylawn,rather

than attaching the scope piggyback on

myobservatorytelescopeinitsdomed

building.

Userscanloosenathumbscrewon

topofthescopetoallowthefiltertobe

rotatedtoplacethepowerinputand

tuning knob in a convenient position.

Thetuningknobhas5click-stops

oneithersideofacentreposition,with

each click changing the transmitted

wavelength by 0.1 Å. When adjusting

theknob,evenslightly,theLEDchanges

fromgreenbacktoyellow.Ittakes

several minutes to stabilise and turn

green again after each adjustment. I

couldn’t see much difference when

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 centre 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

SBoth SS60C and SS60P models come with
a heavy-duty waterproof carry case with plenty
of space for storing additional accessories.

SSPlacing 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 anodised collar.

SThe 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 stabilise each time the knob was adjusted.