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From YouTube: SJAA Imaging 10 19 21 Bob Buchheim Backyard Scientists
Description
“Imaging Projects for Backyard Scientists”. by Bob Buchheim
My purpose tonight is to entice you into applying your imaging skills to a different sort of amateur astronomy – that of the Backyard Scientist – making discoveries, gathering data, and doing research that provides genuinely knew information about the universe, pushing the boundaries of the “unknown” a little bit farther out. If you can take a decent astro-image, you can also make scientifically-useful measurements of astronomical phenomena, such as stellar variability, the rotation and shape of asteroids, and binary-star orbits.
A
All
right
well
welcome
to
the
october
sjaa
imaging
sig,
and
tonight
we
have
bob
buckheim
who's
going
to
tell
us
about.
I
guess
I'd
call
it
citizen
science,
but
I'll.
Let
bob
describe
it!
You
could
see
here
a
picture
of
bob
he's
the
one
on
the
right.
He.
He
told
me
that
a
long
time
ago
these
two
kids
dreamed
of
being
astronomers.
A
Neither
one
made
it
the
little
guy
on
the
right
after
he
grew
up
and
had
some
disposable
income
still
wondered
whether
there
was
a
way
for
amateurs
to
participate
in
this
astronomical
research
and
it
turned
out.
There
were
quite
a
few
ways
enough
to
fill
a
book
or
two,
so
bob
wrote
those
two
books
and
he's
going
to
tell
us
about
them
tonight.
B
B
B
The
important
thing
for
tonight
is
that
if
you
can
make
a
halfway
decent,
astro
image,
then
you
can
do
any
of
the
things
that
I'm
going
to
tell
you
about
the
topic
tonight
is:
can
amateurs
contribute
to
astronomical
research
now?
Obviously,
we
cannot
compete
with
the
professional
astronomers
because
we
live
in
two
entirely
different
worlds:
they're
up
there
and
we're
down
here.
B
So
my
plan
is
to
see
if
I
can
entice
some
of
you
into
that
dark
side
of
amateur
astronomy,
doing
science
things
I'll
spend
about
a
half
hour,
telling
a
few
stories
about
how
you
can
use
your
imaging
equipment
for
discovery
and
for
measurement
and
then,
if
any
of
this
actually
sparked
some
interest.
We'll
have
plenty
of
time
to
discuss
the
details.
B
B
Two
images
taken
some
time
apart
and
blinked
is
how
jay
was
not
the
discoverer,
but
these
two
guys
one
in
germany
and
one
in
sweden,
were
the
discoverers
of
that
nova
near
m27
just
back
quite
a
while
ago,
and
and
they
were
using,
you
know,
modest
amateur
scale,
equipment,
a
c11,
and
I
don't
even
remember
what
a
comp
star
was,
and
you
know
old
starlight
express
cameras.
The
deal
was
they
took
advantage
of
their
observing
time
and
they
took
the
time
to
blink
their
images.
B
Now
most
of
you
take
subs
and
sum
them
in
order
to
get
your
deep
images
take
the
time
to
blink
them.
You
never
know
what
you
might
find
in
there.
I
remember.
I
think
it
was
about
five
years
ago,
a
fellow
down
in
south
america
was
taking
a
picture
of
some
galaxy.
You
know
five-minute
subs
for
several
hours
and
he
captured
the
initiation
of
a
supernova
never
been
done
before,
but
he
was
in
the
right
place
at
the
right
time
now,
if
you're
planning
on
making
a
discovery.
B
B
Point
your
telescope
and
camera
right
there.
The
story
is:
there's
a
recurrent
nova.
It's
been
observed,
I
think
five
times
now.
Its
recurrence
time
seems
to
be
just
about
exactly
one
year.
Maybe
six
months
there's
been
some
space-based
x-ray
stuff.
That
said,
something
was
going
on
in
the
intervening,
but
of
course
it's
observable
by
us
now,
six
months
from
now
it'll
be
behind
the
sun,
based
on
the
last
two
or
three
outburst
events.
B
B
B
We
need
to
do
continuous.
You
know
every
night,
if
possible,
imaging
of
this
thing
after
it's
detected
based
on
the
prior
eruptions.
It'll
probably
be
visible
and
measurable
for
us
for
two
three
weeks
after
the
initial
eruption,
and
our
images
and
photometry
derived
from
them
will
be
useful
because
those
big
professional
and
space-based
observations
are
likely
to
be
snapshots
in
time
and
our
continuous
record
of
photometry
on
a
guy
like
this
helps
to
put
those
in
context.
What
was
going
on
between
those
professional
observations?
B
So
that's
action
item
number
one
for
you
m31,
whenever
you're
out
for
the
next
month,
or
so
now
somebody
said
photometry,
which
is
one
of
my
favorite
things:
the
science
of
measuring
the
brightness
and
color
of
objects
in
the
sky.
It's
amazing
the
number
of
things
that
are
in
fact
variable
when
you,
when
you
look
at
them,
there's
almost
all
of
the
astro
imaging
programs
that
that
we
use
maxim,
astro
art
aip
for
win.
B
It's
not
just
the
target
that
you
need
to
pay
attention
to
for
your
target,
your
photometry
software,
when
you
tickle,
the
right
keys,
will
put
an
aperture
around
that
target
two
or
three
rings
inside
the
center
ring
it'll,
add
up
all
of
the
adus
on
all
of
the
pixels
in
there.
That
tells
you
how
much
light
came
from
the
target
object
in
that
image,
but.
B
B
B
So
fundamental
concept,
number
one
is
differential
photometry
in
addition
to
your
target.
You
want
to
identify
in
that
same
image,
a
star
that
is
known
to
be
constant
in
brightness
and
whose
magnitude
is
known,
usually
you're,
going
to
want
to
have
a
third
star
so
that
you
can
be
a
check
that
your
comparison
star
is
indeed
constant
in
brightness
and
not
changing,
but
then
you're
having
told
it.
Here's
my
target.
B
Here's
my
comp
star,
here's
the
aperture
sizes
that
photometry
routine,
will
take
a
sequence
of
images
and
it'll
do
some
math
on
each
of
them
to
give
you
a
graph
or
table
of
numbers.
That
is
the
brightness
of
your
target
and
magnitudes
versus
time
and,
as
they
say,
almost
all
of
the
popular
image
processing
softwares
will
have
a
tool
like
this,
so
you
don't
worry
about
the
math
it'll.
Take
care
of
that.
B
B
Tell
it
what
the
comparison
star
magnitude
is
and
push
go
and
the
output
will
be
a
table
or
a
graph
of
target
brightness
over
time
concept.
Number
two,
then,
is:
what
do
we
mean
by
good
images
for
photometry
in
general?
Well,
absolutely
you
have
to
pick
your
exposure
so
that
the
adus
on
your
target
and
your
comparison
stars
are
within
the
linear
range
of
your
camera
and
I'm
guessing
that.
B
Most
of
you
understand
what
what
I
mean
by
linear
range,
no
saturated
pixels,
usually
if
you're
on
a
using
a
16-bit
camera,
you
don't
want
the
peak
adus
in
any
star
image
to
be
over
about
50
000.
If
you
have
non-anti-blooming
gates,
maybe
half
that
and
the
processing
you
do
is
bias
dark
and
flat,
and
that's
it.
No
deconvolution,
no
sharpening
anything
like
that,
and
the
other
thing
is
try
for
well-sampled
point-sped
productions.
B
Don't
don't
have
square
stars
where
the
star
image
is
smaller
than
your
pixel
don't
bend,
ideally
three
or
four
pixels
across
the
full
width.
Half
max
of
your
point
spread
function.
An
example
like
this
might
be
a
little
bit
of
overkill,
but
you
can
see
that
you
see
the
whole
smooth
point
spread
function.
B
If
you
run
a
profile
across
the
middle
of
it,
you
can
reproduce
the
position
and
the
intensity
distribution
of
the
star
image.
That's
what
you're
looking
for
and
and
when
you
follow
those
rules.
Your
images
are
going
to
look
washed
out,
maybe
a
little
fuzzy,
not
beautiful,
but
they're,
tailored
for
making
accurate
measurements,
which
is
where
the
beauty
of
the
science
comes
from,
and
here's
here's
an
example
of
the
of
a
straightforward
project.
Uzid
sagitta
is
the
target
star
in
this
image.
There's
a
a
comparison
and
a
check
star.
B
This
is
a
plot
of
brightness
along
the
vertical
axis
and
time
and
effect
under
the
on
the
horizontal
axis.
The
pink
line
is
the
observed
magnitude
difference
between
comparison,
one
and
comparison.
Five.
The
fact
that
it's
a
flat
line
means
that
indeed,
both
of
those
stars
were
constant
in
brightness
through
the
the
duration
of
this
project,
and
then
the
blue
line
is
the
object.
The
target
minus
comparison
star
one,
and
you
can
see
that
you
know
it's.
You
know.
B
You
report
that
time
of
minimum
light
to
somebody
like
the
american
association
of
variable
star
observers,
who
compiles
reports
from
everybody
who
looked
at
any
eclipsing
binary
star
in
the
last
six
months
and
makes
that
record
available
to
professional
astronomers.
Now.
Why
would
they
care
about
that?
Because
if,
if
these
stars
are
going
around
each
other,
you
know
like
the
earth
goes
around
the
sun?
B
B
It
turns
out
they
don't
because
many
of
these
eclipsing
binary
systems
there's
something
more
going
on
than
just
a
gravitational
orbit.
Indeed,
on
this
particular
star
uzi
sagitta,
imagine
that
you
had
you've
measured
your
eclipse
and
you
looked
at
the
ephemeris
and
you
calculated.
When
should
it
have
happened
and
the
time
you
measured
and
the
time
it
should
have
happened?
Well,
if,
if
it
happened
right
on
schedule,
the
difference
would
be
zero.
If
it
happened
a
little
early,
then
your
observed
minus
calculated
time
would
be
a
negative
number.
B
B
If
they
were
occurring
right
on
time,
that
would
be
a
bunch
of
dots
that
make
a
flat
line
zero.
The
error
was
always
zero.
It
always
happened
right
on
time
and
you
know
they
probably
a
little
random
errors
and
just
because
of
our
measurements,
certainly
here's
the
observed
minus
calculated
time
over
the
last
70
years
for
uz
sagittar.
B
It's
not
a
flat
line.
The
the
eclipse,
you
know
sometimes
happens.
A
little
early
sometimes
happens
a
little
late
and
the
the
numbers
you
know
the
peak
to
peak
is
it's
sometimes
20
minutes
early,
sometimes
20
minutes
late,
not
a
subtle
thing,
and
if
you
try
to
fit
a
curve
through
those
data
points,
it's
pretty
well
fit
by
a
sine
curve
with
a
period
of
about
47
years.
B
There's
there's
a
probable
cause
for
that
kind
of
a
sinusoidal
variation
in
the
timing
of
the
eclipses,
and
that
is
that
we're
not
looking
at
a
binary
system
we're
looking
at
a
system
with
three
stars:
there's
a
third
star
in
there
widely
separated
in
a
47-year
orbit.
It
does
not
eclipse
either
of
the
center
two,
but
it
tugs
on
them
with
its
gravity
as
it
goes
around.
B
B
Some
of
them
are
exchanging
mass
between
the
two
stars,
some
of
them
there's
a
vibrant,
stellar
wind.
The
whole
system
is
losing
mass,
and
all
of
that
affects
the
timing
of
these
eclipses,
so
observe
minus
calculated
times
on
eclipsing
binaries
is
a
is
a
straightforward,
imaging
and
photometry
project
that
has
a
whole
lot
of
value
in
the
study
of
binary
stars
and
stellar
properties.
B
Our
counter-attack
is
going
to
depend
on
its
composition,
its
size
and
other
properties
like
its
rotation
rate,
and
you
can
do
the
same
sort
of
differential
photometry.
If
you
take
a
you
know,
got
an
asteroid
in
your
field
of
view.
Yeah
it'll
move
a
little
bit
relative
to
the
stars
over
the
course
of
the
night,
but
all
of
those
standard
image
processing
programs
can
handle
a
moving
target
and
you
can
do
differential
photometry
on
that
asteroid
and
the
the
deal
with
an
asteroid
is
it's
not
round
and
they're
pretty
much
gray.
B
They
don't
have
any
color
or
significant
changes
in
surface
brightness.
So
here's
my
asteroid
and
as
it
spins
when
you
see
it
kind
of
edge
on
it's,
going
to
be
a
little
fainter,
because
there's
less
surface
area
reflecting
sunlight
to
you
and
it
comes
around
and
then
it's
going
to
get
brighter
and
fainter
and
brighter.
So
you
expect
that
the
brightness
ought
to
change
if
it's
rotating
here's
an
example.
This
is
real
data
from
asteroid,
755,
quintilla,
son
of
a
gun.
It
gets
brighter
and
fainter
and
brighter
and
fainter.
B
B
Besides
the
rotation
period,
the
delta
magnitude
from
brightest
to
faintest
gives
you
an
idea
of
the
aspect
ratio.
You
know
how,
how
long
is
it
versus
you
know?
How
long
is
it
versus
how
tall
is
it
if
it
was
spherical
as
it
rotates
there,
wouldn't
be
any
brightness
change
at
all?
So
if
you
have
a
flat
line
either
it's
not
rotating
or
it
has
an
aspect
ratio
about
one
to
one:
the
shape
of
the
light
curve.
B
The
fact
that
the
one
the
first
minimum
is
fainter
than
the
second
minimum
and
the
fact
that
there's
this
little
kind
of
inflection
point
going
on
here,
those
all
encode
information
about
the
details
of
the
shape
of
the
object
and,
and
so
there's
a
and
other
things
that
you
can
learn
from
from
these
light.
Curves
the
shape
of
the
object
thing
is
sort
of
amazing.
B
B
So
that's
a
good
thing.
The
problem
with
light
curve
inversion
is
it's
a
shape,
but
it's
a
relative
shape.
You
don't
know
you
know
how
big
is
it
is
it
you
know
one
mile
or
20
miles
across,
but
if
you're
doing
planetary
imaging,
you
already
have
a
high
rate
imager
that
you
use
for
lucky
imaging
on
planets
that
same
technology
can
be
applied
to
a
phenomenon
called
asteroid
occultations.
B
B
B
These
were
almost
all
made
with
two
inch:
three
inch
telescopes
and
video
cameras
back
in
08.
Some
of
them
were
a
camera
behind
a
half
of
a
binocular.
It's
that
you
know
kind
of
crude,
of
an
imaging
thing.
You
don't
have
to
see
the
asteroid,
because
what
you're
looking
for
is
where
the
star
blinks
to
time
it
accurately.
B
B
Double
stars:
visual
double
stars:
we've
all
looked
at
them.
You
know
you
look
in
your
eyepiece
and
at
alberio
and
one's
gold
and
one's
blue
and
they're
beautiful,
not
very
many.
People
have
thought
about
measuring
their
positions
relative
to
each
other
and
measuring
how
that
changes
over
the
years
turns
out.
That's
still
a
vibrant
area
of
research.
B
The
next
time
it
was
measured,
was
12
years
later
and
it
had
moved
it
had
moved
away.
It
was
now
six
arc
seconds
and
the
position
angle
had
rotated
about
20
degrees
and
then,
as
luck
would
have
it
in
this
business,
nobody
looked
at
it
again
until
2007,
when
I
was
working
some
people
that
got
excited
about
visual
double
stars,
and
so
in
2007.
B
That
begins
to
look
like
orbital
motion.
Now
it's
about
time
for
somebody
to
measure
it
again
and
it
probably
needs
another
100
years
of
getting
measured
once
a
decade
to
fill
out
what
that
orbit
looks
like,
but
you
know
double
stars:
eclipsing
binaries
and
visual
binaries
are
really
the
only
way
that
we
know
stellar
masses.
B
B
B
You
know
five
six,
eight
arc,
second,
separation,
that
that
works
with
conventional
ccd
imaging,
but
once
you
get
down
where
the
stars
are
separated
by
you
know
one
maybe
two
times
the
seeing
disc,
you
can't
measure
them
anymore,
they're
too
close
together,
but
use
that
lucky
imaging
concept
that
you
use
for
planetary
imaging
and
you
can
separate
and
measure
one
arc
second
pairs
and
start
to
map
out
their
orbits,
which
are
likely
to
have
shorter
orbital
periods.
So
do
that
I
promised
I'd.
Come
back
and
tell
you
the
story
behind
this
guy.
B
B
The
the
story
of
this
image
begins
when
a
a
professor
at
university
of
colorado
got
a
call
from
a
friend
of
his
who
said:
something's
happened
in
m51
and
we
don't
know
what
it
is
and
we're
not
sure
that
we
can
get
enough
telescope
time
to
really
characterize
it.
Do
you
suppose
that
some
of
your
amateur
friends
might
be
able
to
see
it?
B
So
he
called
wayne
green
wayne
called
woody
sims,
who
called
me
and-
and
we
said
yeah
we'll,
give
it
a
try
anyhow
and
we
went
out
and
and
imaged
m51
yeah.
Not
only
can
we
see
it,
but
it's
absolutely
bright
enough
for
us
to
do
photometry
on
if
we
stack
images
for
about
an
hour's
worth
of
exposure,
so
so
he
said
so
do
and
we
did
and
midway
after
the
first
couple
of
weeks.
Woody
said
you
know.
C
B
B
It's
amazing
what
people
are
doing
in
their
backyards,
to
assist
research,
astronomers
and,
of
course,
buy
my
books.
Please,
projects
like
these
are
a
great
way
of
learning
astronomy
by
actually
seeing
the
phenomena
that
you're
learning
about
with
your
own
images
and
your
own
data
you'll
meet
people,
you
probably
never
would
run
across
in
your
ordinary
life
and
who
knows,
you
may
discover
something
you
may
make
an
important
contribution
and
push
the
boundaries
of
the
unknown
out
a
little
further
in
astronomy.
A
B
A
B
B
If
something
is
changing
on
a
time
scale
of
minutes
or
hours,
you
don't
get
it
on
a
once,
a
night
image.
You
know
that
that
you
know
even
uzi
sagitta
its
period
is
2.2
days
in
round
numbers.
You
know
you
can
go
a
long
time
before
you
see
an
eclipse
at
all
and
with
a
cadence
of
one
shot
per
night
or
for
every
other
night.
B
You
have
no
clue
what
the
actual
period
of
that
is.
The
you'd
think
that
sloan
would
have
put
the
asteroid
light
curve
people
out
of
business,
because
you
know
it.
You
know
it
looks
at
you
know
the
the
ecliptic.
You
know
every
what
is
it
two
or
three
nights
and
it
you
know,
can
see
asteroids
down
to
really
faint,
but
it
can't
measure
them
to
really
bright.
B
So
no
they're
not
going
to
put
us
out
of
business
there
and
and
what
they
probably
are
going
to
do,
is
generate
an
enormous
number
of
follow-up
requests,
because
they're
going
to
see
something
happening
and
they're
going
to
go
well.
Somebody
with
telescope
time
needs
to
stare
at
this
for
a
while,
so
yeah.
C
A
A
C
C
D
C
There
kind
of
more
yeah-
and
I
did
some
googling
while
you
were
talking
and
and
doesn't
seem
like
there's
a
a
a
crisp
introduction
for
you
know
in
the
last
five
years.
Basically
right
when
the
technology
has
has
changed,
there's
there's
a
whole
bunch
of
imaging
programs.
Now,
where
there
used
to
be
only
two,
and
now
we
have
you
know
cmos
cameras
of
all
flavors
that
are
much
less
expensive
than
than
ccds.
B
Yeah
there's
two
things
I'll
I'll
admit.
I
have
to
plead
ignorance
regarding
the
software
that
you
you
all
using
I'd,
be
curious
to
know
what
it
is,
but
for
all
of
the
differences
between
ccd
and
cmos
once
you've,
characterized
your
cmos
imager,
it
can
do
fine
photometry,
there's
a
lot
of
well.
You
know,
jim
knows
gary
walker
he's
using
cmos
cameras,
doing
great
photometry
a.
D
D
A
C
B
D
B
So
your
your
cmos
camera
will
take
good
images.
You
know,
linear
and
and
well
sampled,
and
then
they're
they're,
either
free,
like
aij
or
low
cost
like
v
photo.
You
have
to
be
an
aavso
member,
but
85
bucks
a
year
and
aip
for
win,
which
is
a
pretty
capable
astronomical
image.
Processing
program
is
now
unlicensed,
no
dinero
involved.
A
Just
I
you
know,
like
I
say
I
did
my
I
had
a
little
project.
I
gave
myself
to
do
a
eclipsing
star.
I
forgot
what
it
was.
I
looked
it
up
on
on
there's
a
website
that
tells
you
what
what's
going
to
eclipse
what
and
you
know
at
what
time
and
all
that
yeah
it
was.
You
know
I
gotta
like
her.
It
was
straight,
show
it
and
show
it.
A
Oh
it'd,
take
me
ten
minutes
to
find
it
the
one
bone
I'll
pick
about
with
what
you
said
was
that
it
was
no
two
or
three
magnitudes.
I
mean
it
was
probably
.05
magnitude
or
0.02
magnitude.
You
know
it
was
tiny.
You
know
it
was
buried,
but
you
know
with
enough
data.
I
could
pull
it
out,
but
are
there
really?
I
guess
that's
my
question.
Yeah
yeah.
B
Yeah
they
they
come
in.
All
flavors
like
like
you've
observed.
You
know,
if
the
if
the
eclipse
is
is,
you
know,
only
very
partial,
just
kissing
each
other
and
then
they're
about
equal
brightness,
yeah
they'll
be
a
very
small
delta
magnitude.
Well,
you
I,
if
you
go
to
the
aavso
website,
public
access
will
take
you
to
a.
I
don't
remember
the
name
of
it,
but
there's
a
search
capability.
B
We
can
say
I
want
to
know
eclipsing
binaries
in
this
constellation,
that's
something
that's
conveniently
placed
in
the
sky
and
then
it'll
give
you
a
list
and
you
can
check
what
the
delta
magnitudes
are,
and
you
know
pick
a
big
one.
If
that's
what
you're
looking
for,
but
on
the
other
hand
you
know
think
about
it.
You
got
a
light
curve
that
reliably
observed
a
.05
magnitude
change.
E
B
And
that's
nowhere
near
the
limit
of
what
you
can
do
with
a
small
telescope
and
an
electronic
image
running
ccd
or
cmos
last
year.
A
high
school
girl
here
in
gilbert,
contacted
me,
wanted
to
do
a
science,
fair
project
about
exoplanets,
and
so
she
used
my
observatory
to
observe
an
exoplanet
transit.
You
know
there's
the
star
and
the
planet
you
know
passes
in
front
of
it
and
the
and
the
starlight
brightened
by
a
little
less
than
one
percent
about
.01
magnitude,
absolutely
clean
signals.
She
was
able
to
get.
B
A
D
D
D
A
B
A
D
A
A
D
And
if,
if
you
want
to
ai
aij,
has
a
pretty
significant
learning
curve,
but
if
you
want
to
do
it
even
easier,
there's
a
guy
at
nasa
named
rob
zellum
who
created
a
program
called
exoplanet
watch
and
if
you
just
google
exoplanet
watch,
you
can
find
it
and
he's
wrote
a
python
script
and
all
you
do.
Is
you
take
your
series
of
images?
B
Curves
and
again,
a
lot
of
them
are
outside
the
ability
of
the
professional
astronomy
community
to
deal
with.
You
know
all
the
all
this
stuff
about
beetlejuice
and
the
great
dimming.
The
lion's
share
of
the
data
came
from
backyard
observers,
because
you
know
you
go
to
mount
palomar
and
stare
at
beetlejuice
you're,
going
to
melt
something.
A
A
B
C
B
B
Well,
obviously,
you
you
you're
a
little
more
limited
than
if
you're
in
a
nice
dark
place,
but
imagine
differential,
photometry,
you're
kind
of
subtracting
out
the
sky
glow.
The
noise
in
the
sky.
Glow
is
still
there,
but
the
the
offset
you
subtract
out
and
you
focus
on
targets
that
are
bright
enough,
that
you
get
a
good
signal
to
noise
ratio
without
saturating
your
imagery.
You
know
it.
You
know
you,
you
get
a
little
there's
a
limit
there,
but
you
can
still
do
productive
work.
B
D
B
I
made
a
light
curve
of
algol
eclipse
using
a
old
canon
dslr
and
its
kit,
50
millimeter
lens
yeah,
just
put
it
on
a
and
a
barn
door
mount
not
even
a
telescope
mount
and
here's.
The
thing
remember:
I
talked
about
timing,
the
eclipses
and
then
contributing
the
the
eclipse
time
to
the
record.
If
you
look
at
the
observed
minus
calculated
time
history
of
algol
it
it's
like
the
stock
market,
it's
there
are
a
lot
of
interactions
going
on
in
algo.
B
There
are
more
than
two
stars
in
there.
I
think
some
people
think
there's
four
or
five
and
there's
some
kind
of
a
either
magnetic
or
wind
interaction
going
on.
There's
a
lot
of
physics
happening
up
there,
that
you
need
a
continuous
record
of
eclipse
timings
to
keep
track
of
it,
and-
and
you
can
do
that
with
really
small,
simple
equipment
from
a
horribly
light,
polluted
area.
C
B
B
D
E
B
About
filters
at
all,
and
you
you
probably
know
that
professional
photometry
uses
a
whole
different
set
of
filters,
spectral
prescriptions
than
than
tri-color
imaging.
Does
you
know
you
use
rgb
the
the
photometrists
use
b,
v
and
r,
and
maybe
I
but
there
are
projects
where,
frankly,
it
doesn't
matter
because,
like
in
the
eclipsing
binary
time
and
minimum
thing,
all
you're
trying
to
see
is
the
bottom
of
that
curve
and
and
filtering
can
be
useful.
But
it's
not
mandatory.
A
Yeah
the
thing
I
wanted
to
add
to
paulo's
question
was
what
I
learned
from
that
exoplanet
transit
project.
I
did
was
that
you
know
you
can
do
it
with
light
pollution,
but
what
you
trade
off
is
time
resolution,
so
you
know
you,
you
won't
be
able
to
make
measurements.
You
know
you
know
accurate
to
the
minute
because
you're
going
to
need,
you
know
20
minutes
of
of
exposure.
You
get
a
good
mag.
You
know
measure
you
get
a
qualitative,
not
quantitative
response
right,
I'm
just
saying
so.
A
You
won't
be
able
to
get
these
sharp
curves
because
well
that
first
thing
that
I
showed
earlier
where
it
was
just
so
noisy
was
that
was
my.
You
know:
30
second,
exposures
of
the
of
the
star
and
yeah
the
stuff
was
all
over
the
place
and
then
what
I
did
was
I
took
a
moving
average
of
those
points
and
then
I
got
the
dip,
and
so
you
know,
of
course
I
lost
time
resolution
when
I
did
that
moving
average,
and
so
you
can
do
stuff,
but
you
know
you
won't
be
able
to
measure.
A
B
And-
and
you
know
in
the
in
the
eclipsing
binary
world,
our
our
friend
wayne
green
a
couple
of
years
ago
was
doing
a
project
with
some
student
and
he
couldn't
find
the
eclipse.
He
looked
at
the
ephemeris
and
said
by
golly.
You
know
12
o'clock
tonight
and
it
wasn't
there
and
and-
and
he
roped
me
into
helping
and
it
took
us-
I
think,
a
week
of
nights
to
track
down
the
o
minus
c
curve.
C
B
Minute,
but
but
a
minute
per
orbit
times,
50
years
you
didn't
even
know
what
night
the
eclipse
was
gonna
happen
on,
and
and
so
you
know
you
you
come
along
now
and
say:
okay,
I've
measured
it
tonight
and
my
measurement
is
good
to
a
minute.
Well
shoot.
You
know
that
is
a
gigantic
improvement
over
the
situation
before
you
made
that
measurement.
B
A
B
B
D
They
do
there
is
they
they
essentially
take
a
clock.
A
gps
clock
and
put
the
put
the
clock
in
the
frame
of
the
image
is
one
way
that
they
go
about
it
and
then
there's
one
of
the
qhy
cameras
actually
has
a
gps
clock
built
into
the
camera
and
specifically
for
doing
those,
but
it
just
depends
on
the
kind
of
science
that
you're
trying
to
do
how
accurate
your
time
needs
to
be.