tops 2003 remote obs 1 karen meech institute for astronomy tops 2003 image copyright, r. wainscoat,...

TOPS 2003 TOPS 2003 Remote Obs 1Remote Obs 1

Karen Meech Karen Meech Institute for AstronomyInstitute for Astronomy

TOPS 2003TOPS 2003

Image copyright, R. Wainscoat, IfAImage copyright, R. Wainscoat, IfA Image courtesy K. MeechImage courtesy K. Meech

How to Observe?How to Observe?

The TOPS modelThe TOPS model Amateur “fun”Amateur “fun”

TOPS 2002TOPS 2002

How to ObserveHow to Observe

Professional Professional ObservingObserving Request Telescope Request Telescope

timetime Request MoneyRequest Money Ultra-preparedUltra-prepared Each nano-sec is Each nano-sec is

preciousprecious

Images, Courtesy K. MeechImages, Courtesy K. Meech

Queue SchedulingQueue Scheduling

Section of TargetsSection of Targets Time critical?Time critical? Plan exposure times, Plan exposure times,

filtersfilters Auto-schedulerAuto-scheduler

Optimizes observingOptimizes observing Flexible for conditionsFlexible for conditions No interactivityNo interactivity Many chances for dataMany chances for data

Notification of data Notification of data receiptreceipt

Image, Courtesy K. MeechImage, Courtesy K. Meech

STScISTScI

Types of Types of ObservationsObservations

BrightnessBrightness Hipparcos Hipparcos magnitudes magnitudes m = -2.5 log (B) + cm = -2.5 log (B) + c

Brightness vs TimeBrightness vs Time Intrinsic variabilityIntrinsic variability Other changesOther changes

Wavelength InformationWavelength Information PositionPosition MorphologyMorphology

SizeSize StructureStructure

PhotometryPhotometry Measure of accumulated Measure of accumulated

light arriving at detectorlight arriving at detector

AstrometryAstrometry Precise measurement of Precise measurement of

positionposition Transformation of 3-D sky Transformation of 3-D sky

onto a 2-D surfaceonto a 2-D surface

Surface brightnessSurface brightness Brightness per unit areaBrightness per unit area


PhotometryPhotometry

Counting up how Counting up how much light falls on the much light falls on the detector from stardetector from star

ApertureAperture How big to use?How big to use?

Sky BackgroundSky Background Where to measure?Where to measure? How?How? Background objectsBackground objects

Images, Courtesy J. BauerImages, Courtesy J. Bauer

Surface Surface BrightnessesBrightnesses

Measure of Measure of brightness per unit brightness per unit areaarea

Point sourcesPoint sources Brightness does not Brightness does not

depend on aperture depend on aperture sizesize

Brightness profilesBrightness profiles Dust activityDust activity Measure of amount of Measure of amount of

materialmaterial Falloff Falloff gravity field gravity field Missing massMissing mass

Image, Courtesy K. MeechImage, Courtesy K. Meech

NASA, STScINASA, STScI

Surface Brightness PhotometrySurface Brightness Photometry

Measure light in Measure light in central aperturecentral aperture

Measure light in Measure light in successive annulisuccessive annuli

Plot brightess (mag) Plot brightess (mag) versus areaversus area Mag / arcsecMag / arcsec22


Some ExamplesSome Examples

Images, Courtesy K. Meech & J. BauerImages, Courtesy K. Meech & J. Bauer

Beta PictorisBeta Pictoris

Absolute PhotometryAbsolute Photometry

AbsoluteAbsolute True brightnessTrue brightness Photometric (Eggen-o-Photometric (Eggen-o-

metric)metric) Requires standardsRequires standards

““Know thy celestial Know thy celestial sphere”sphere” Extinction; seeingExtinction; seeing HA = 0HA = 0 Depends on Depends on

declinationdeclination


Copyright R. WainscoatCopyright R. Wainscoat

Differential Differential PhotometryPhotometry

Relative brightnessRelative brightness Tolerates some cloudTolerates some cloud Corrects for extinctionCorrects for extinction

AirmassAirmass cloudcloud

Measure many stars Measure many stars as referenceas reference Noise & repeat Noise & repeat

measurements – S/Nmeasurements – S/N


Differential Differential Light curveLight curve


ResolutionResolution

TelescopeTelescope Res = 1.22 Res = 1.22 /D/D

Atmosphere – seeingAtmosphere – seeing Seeing depends on Seeing depends on

Angular SizeAngular Size S = r S = r

Plate scalePlate scale Arcsec / pixelArcsec / pixel


Images from Yerkes Obsty.Images from Yerkes Obsty.


Know your observing Know your observing sitesite MKO MKO superb seeing superb seeing Lowell Lowell worse worse

Conditions are time Conditions are time variablevariable

NASA ImagesNASA Images

AstrometryAstrometry Precise position measPrecise position meas Map 3-D sky to 2-D Map 3-D sky to 2-D

imageimage TechniqueTechnique

Measure “centroids” of Measure “centroids” of many starsmany stars

Fit for plate centerFit for plate center Fit for scale, rotationFit for scale, rotation Fit for warping, stretchingFit for warping, stretching

RequirementsRequirements Finding the objectsFinding the objects

BlinkingBlinking Different color planesDifferent color planes memorizationmemorization

6.6’ FOV (1/2 CCD) [above]

40” section [lower]


Colors & SpectroscopyColors & Spectroscopy

Chemistry vs distance Chemistry vs distance origins origins

Spectroscopy is best Spectroscopy is best tool for compositiontool for composition

Colors – a “poor man’s” Colors – a “poor man’s” solutionsolution


The Wild & Wonderful World The Wild & Wonderful World of Filtersof Filters

Figure, Courtesy K. MeechFigure, Courtesy K. Meech

HST – Cone NebulaHST – Cone Nebula

tops 2003 remote obs 1 karen meech institute for astronomy tops 2003 image copyright, r. wainscoat,...

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