Process overview - abstract
Quick peek target
lightcurve with
raw target
instrumental
magnitudes
Start
Acquire field images
- Reference
- Target
Reduce
-Transforms
-Color index
-Extinction
Calibrate images
Convert target field
to standard
magnitudes
Extract magnitudes
Plot target lightcurve
with standard
magnitudes
Choose
plot
Entire
lightcurve phase
obtained ?
yes
no
Gather more lightcurve
phase data to fill-out
the curves entire phase
End
Process overview – package based
Start
MPO Canopus
Quick peek target
lightcurve with
raw target
instrumental
magnitudes
Calibrate images
Acquire field images
- Target
- Comparisons
- Object
Choose
plot
Plot target lightcurve
with standard
magnitudes
Extract target
magnitudes
import
Acquire field images
- Reference
- Color Index
- Extinction
import
PhotoRed
Reduce - Target
-Color index
-Extinction
Convert target field
to standard
magnitudes
Calibrate images
Extract reference
magnitudes
Reduce - Reference
-Transforms
-Color index
-Extinction
Acquire images – two alternative workflows
Basic hi-low method
High color index
reference field –
V,R,C Landolt,
Henden
<2º
Continuous
target field –
V or C, V
preferred
Continuous VRC method
Best
comparison
star in target
field
High color index
reference field –
V,R,C Landolt,
Henden
High-low
extinction
reference field –
V,R,C Landolt
Continuous
target field –
V, R, C
Low extinction
“reference” field
– V,R,C
<2º
“High” extinction
“reference” field
– V,R,C
Best
comparison
star in target
field
PhotoRed reduction coefficients set from acquired images
Basic hi-low method
Transforms
High color index
reference field – V,R,C
Landolt, Henden
<2º
Continuous
target field – V
or C, V
preferred
Comps
Standard Mags
Best
comparison
star in target
field
First-Order
Comps
Color Index
(Comps/Target)
Target
Standard
Mags
High-low extinction
reference field –
V,R,C Landolt
First-Order
All Sky
PhotoRed reduction coefficients set from acquired images
Continuous VRC method
Transforms
High color index
reference field – V,R,C
Landolt, Henden
“High” extinction
“reference” field –
V,R,C
<2º
Continuous
target field – V,
R, C
Comps
Standard Mags
Best
comparison
star in target
field
Low extinction
“reference” field –
V,R,C
First-Order
Comps
Color Index
(Comps/Target)
Target
Standard
Mags
First-Order
All Sky
Process – overview – Three methods to convert to standard
magnitudes

Only one of the three methods – the basic “rigorous” method
is graphed here, using only the basic “high-low” imaging
method.
PhotoRed
Calibrate images
Reduce - Target
-Color index
-Extinction
Convert target field
to standard
magnitudes
Report to
MPO Center
Extract reference
magnitudes
Reduce - Reference
-Transforms
-Color index
-Extinction
Basic rigorous
- can use
in all cases
Binzel
- use where
comp stars
of same color index
are in target field
Quick Mags
- use for
long-period
AAVSO variables
Report to
AAVSO
Extract target field image data
MPO Canopus
Acquire field images
- Target
- Comparisons
- Object
Target
Reference
field image
Field image
in
low-high in
V and/or C
V,R and C
Choose best
comparison star
Calibrate images
Extract
data
(Lightcurve
wizard)
Save image of
comp stars &
note best
comp star
Make
observations
*.FF2 files
Extract target
magnitudes
View raw
comparison
plots
Comparison
stars
variable?
no
or
Quick peek target
lightcurve with
raw target
instrumental
magnitudes
Continue
– import data to PhotoRed
yes
Choose other
comparison
stars or
reshoot session
Extract reference field data - reduce transform coefficients
PhotoRed
Acquire field images
- Reference
- Color index
- Extinction
Extract target
magnitudes
Calibrate images
Reduce - Reference
-Transforms
-Color index
Deselect outliers
yes
Reference
Reference
field
Fieldimage
image
highlow-high
color-index
in
V,R and C
Extract
data
(Photometry
wizard)
Reduce - Reference
Transforms
Color index
Make
observation
*.obs files
View
transforms
plot
Comparison
stars
plot bad?
no
Set transform
coefficients
Reduce - Reference
Errors
View
errors
plot
Transform error
plot bad?
yes
no
Continue
– To set rough extinction
Deselect outliers
Extract reference field data - reduce rough extinction coefficients
PhotoRed
Acquire field images
- Reference
- Color index
- Extinction
Calibrate images
Extract target
magnitudes
Reduce - Reference
-Transforms
-Color index
Deselect outliers
yes
Reference
Reference
field image
Field image
high-low
low-high in
extinction
V,R and C
Extract
data
(Photometry
wizard)
Make
observation
*.obs files
Reduce - Reference
Extinction
“First Order –
All Sky”
View
extinction
plot
Extinction
plot bad?
no
Set rough
extinction
coefficients
Continue
– To set target extinction
Reduce target field – fine-tune extinction (modified Hardie)
MPO Canopus
PhotoRed
import
Extract target
magnitudes
Import
target field
data from
MPO Canopus
Make
observation
*.obs file
Reduce - Target
-Color index
-Extinction
Make special
single group table
Store special
observation
*.obs file
Reimport
original target
field data from
MPO Canopus
Deselect outliers
yes
Reduce – Target
Extinction
“First-Order
Comps”
Note on best
comp star in
target field
View
extinction
plot
Use only 1 best of 5
possible
comp stars
Extinction
plot bad?
no
Set target fine
extinction
coefficients
Continue
– To set target
color index
coefficients
Reduce target field – set color index coefficients
MPO Canopus
Extract target
magnitudes
PhotoRed
import
Reduce - Target
-Color index
-Extinction
Deselect outliers
yes
Original target
field data from
MPO Canopus
Reduce – Target
color index
“Color-index
(Comps/Target)”
View
color index
plot
Color index
plot bad?
no
Set target
color index
coefficients
Continue
– To set standard
magnitudes
Reduce target field – standard magnitudes of comparison stars
PhotoRed
Reduce - Reference
-Transforms
-Color index
-Extinction
Coefficients in
Reductions
dialogue
Reduce - Target
-Color index
-Extinction
Convert target
comp stars to
standard magnitudes
“Comps Standard Mags”
Target field stored special
observation
*.obs file
Save the
Reductions tab
coefficients
Convert target field
to standard
magnitudes
Coefficients in
Reductions
dialogue
Target field original
observation
*.obs file
Make
standard mag
*.FF2 archive
file
Continue
– To plot lightcurve
Convert target
to
standard magnitudes
“Target Standard Mags”
Plot lightcurve
PhotoRed
Convert target field
to standard
magnitudes
Standard mag
*.FF2
File from
PhotoRed
Plot raw
target magnitudes
(Julian Day scale)
MPO Canopus
import
Import
standard mag
target field data
from PhotoRed
to MPO Session
Estimate
period
Plot target lightcurve
with standard
magnitudes
Multiple
session
data
Plot refined
target magnitudes
with aligned phases
(phase scale)
Extract
choose
sessions to
plot
Best period
estimate?
no
yes
Print/save
aligned lightcurve
plot
Acquire more images until lightcurve phase is filled-out
MPO Canopus
End
yes
Acquire field images
- Target
- Comparisons
- Object
Plot target lightcurve
with standard
magnitudes
Entire
lightcurve phase
obtained ?
no
Print/save
aligned lightcurve
plot
Data for entire
phase plotted?
yes
no
Identify
missing
phase portions
Get Julian Date
of minimum
point
Gather more lightcurve
phase data to fill-out
the curve’s
entire phase
Find next
opportunity to
Image missing
phase segment
with
time-of-minimum
calculator
End
To start – acquire
more images