three fundamental “sciences” measuring “distance”, position & “scale” astrometry...

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Page 1: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”
Page 2: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Three Fundamental “Sciences”

• Measuring “Distance”, Position & “Scale” Astrometry

• Measuring Brightness and Intensity Photometry

• Measuring “Colour” Spectroscopy

Exciting science that you can do from the back yard!

Page 3: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Astrometry

How big are the lunar features in this image?

August 29, 2012H-alpha filter0.001 s exposureED80Atik 314L+ cameraTKUCO

Page 4: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Some Math …

RS

The Small Angle Formula R = S where:• R = distance from object• = angle that the object subtends in the sky• S = distance across the object

* Angle in radians

Page 5: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

The Scale of Your Telescope• Scale in (seconds of arc)/mm found by:

• In the previous image a ED80 telescope was used so the scale is (206265)/(600 mm) = 343.8 “/mm

• The Atik 314L+ has 6.45 m pixels, so each pixel has a scale of 342.8”/mm × 0.00645mm/px = 2.22 “/px when used with the ED80

• By measuring the number of pixels you can measure the angle that an object or feature subtends

scalefocal length206,265

Page 6: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

850 px = 3457 km(0.5% error)

304 px = 1236 km

Distance = 0.002524 AUs r

pxs AU 149 598 000 km/AU)

s km px

2.2"/(0.002524 )(

206265"4.027 /

Page 7: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Some other images…

• Capuanus Crater:– December 26,2009– C14, f/11 – Imaging source DMK2104 – 2000 frames– Distance = 0.002523 AU– Scale = 0.20”/px = 0.37 km/px

Page 8: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

• Apennines (Eratsothenes, Archimedes)

– March 1, 2012– C14, f/7– Atik 314L+– 20 frames (0.005 s)– Scale = 0.52”/px– Distance = 0.00262 AU

Page 9: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”
Page 10: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

• Jupiter– November 5, 2011– Distance = 3.98101 AU– C14, f/11– Imaging Source DMK2104– LRGB (~2000 frames each)– Scale = 0.29”/px =

837 km/px 170 px =142 000 km

159 px = 133 000 km

Oblateness = (142 -133)/142 = 6.3%

Page 11: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

• M57– August 26, 2011– C14 f/7– ST7E– LRGB– Distance = 2300 ly– Scale 1.49”/px =

0.017 ly/px

160 px = 2.7 ly

Page 12: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

• M15– August 21, 2011– C14 f/7– ST7E– LRGB– Distance = 33 Kly– Scale 1.49”/px =

0.238 ly/px

534 px = 127 ly

Page 13: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Photometry – Measuring Changes in Brightness

• Intrinsic Variables– Scuti– SX Phe

• Novae and Supernovae• Cataclysmic Variables

Page 14: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Consumer grade CCD cameras…• Capable of doing excellent science!• Modest cost (< $2000)• Excellent software support• Monochrome with no anti-blooming is

preferred• Pixel size should be carefully matched

to image scale – need to oversample• Capable of milli-magnitude precision

photometry

Atik 314L+

SBIG ST7E

Page 15: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

SX Phoenicis Variables

• BL Camelopardalis– Average mag 13.1 – Period

• 0.0389d• 56 minutes – this is

an exciting system to watch!!

40 s integration, C14 f/7ST7E camera – KAF400 detector

Page 16: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

November 9, 2009

The Light-Curve…

November 9, 2009, (C2-C1) = 0.007 mag

BL CamTeff 7730 KAge ~4GaMetal poorPeriod shows a Small change over time!

Page 17: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

DY Pegasi … A Nice Intro to SX Phe

• A great star!– Bright (m = 10.3)– Excellent Check and

Comparison stars– Well placed for fall

observations

Data collected with 8” Newtonian and SpectraSource Lynxx (TC211)

Page 18: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Cataclysmic Variable Stars

• Binary stars that are exchanging mass

• One of the stars is compact• Hot spot forms on accetion

disk• Accretion disk around

compact star produces variability

• A rewarding study for amateurs!

Page 19: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Two exemplar CVs…• DW Uma

– Period (d) 0.136606– Mag 14 - 18

TKUCO 120 s image 0.32 f/4.8

Page 20: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

• GK Persei– Period (d) 1.996803 d– Mag 11.5 - ?

TKUCO 60 s image 0.32 f/4.8

Page 21: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Other Photometric Delights!• Novae and Supernovae• Algol systems• Asteroids

September 29, 2004SN 2004ET0.32 f/4.8 Newtonian ST7E camera

NGC 694630s exposure

Page 22: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Spectroscopy

• Broad and Narrow band filter imaging• Low Resolution Spectroscopy• Medium – High Resolution Spectroscopy

Page 23: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Broadband Colour Imaging

L

R

G

B

M27 LRGB, August 2011, C14 f/7ST7E

Page 24: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Narrow Band Imaging

• H• H• SII• OIII

Page 25: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

H S II O III

C14 f/7Atik 314L+March 1, 2012

Page 26: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

LRGB image of central region of M51 C14 f/7 ST7E

L filter with H overlay showing star forming regions along spiral arms

C14 f/7 Atik 314L+

Page 27: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Stellar Spectra (Low R)

• Remarkably easy to do – even with modest equipment!– Small telescope w/wo tracking– CCD or DSLR– Rainbow Optics or Star Analyzer grating

• Introduces a fascinating new direction for amateurs

Page 28: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Some samples… (trailed images with Atik 314L+, Orion 80 mm ED)

Page 29: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Vega, Teff = 9600 K

Altair, Teff = 6900 K – 8500 K

Altair is a very fast rotator and is squished like a football!

Hotter at the poles by about 20%

Ca II line

Note Deneb’s narrow lines!

Page 30: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Other Interesting Stars…

T = 31 000 K

T = 7 100 K

T = 8 400 K A5

F2

B0.5e

Be Star with disk

Which is these is the hottest star?

Page 31: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Planetary Nebulae

The “Eskimo” – NGC 2392C14 f/7 10 minutesApril 21, 2011

The reason nebula filters work!

Page 32: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Measuring the Expansion of the Universe!

3C273 C14 f/7 60 minutesST7E April 5, 2011

Rest Frame (A)

Measured (A)

z

H 4860 5666 806 0.166

H 6563 7562 990 0.151

z

Zaverage = 0.159

Page 33: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Universal Expansion

• What does z = 0.159 mean?– Apparent recessional velocity is 0.159C = 47 700 km/s!– Hubble expansion law:– Hubble’s constant H = 70 km/s/Mpc– R = 681 Mpc = 2.2 billion light years!

v HR

Page 34: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Medium/High Resolution Spectroscopy• For more advanced work• Requires robust mount and

tracking• Need as much aperture as

possible• BUT – still well within the

reach of advanced amateurs and astronomy clubs!

Page 35: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

The L200 Littrow Configuration

• Can resolve to about 1 A (R = 3000)• Built from a kit, cost ~$1000• Capable of useful research on Be, WR and

Algol type stars (and much more!)

Page 36: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

The Solar Spectrum

ST7E on C14

Page 37: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Altair

Page 38: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Homebrew for under $200!

And it Works!

Page 39: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

The Magnesium Triplet…

R > 5000!

Page 40: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”

Some References…

• Christian Buil - http://www.astrosurf.com/buil/

• Tom Field - RealTimeSpectroscopy (RSPEC) http://www.rspec-astro.com

• Rainbow Optics Spectroscopes http://www.starspectroscope.com/

• Center for Backyard Astrophysics (CBA) http://cbastro.org/

Page 41: Three Fundamental “Sciences” Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”