comet observation during the advent semester of 2007 matt greenwood

Comet Observation during Comet Observation during the Advent Semester of the Advent Semester of

20072007Matt GreenwoodMatt Greenwood

OutlineOutline

Background to CometsBackground to Comets ““Observing”/Analyzing CometsObserving”/Analyzing CometsObserved CometsObserved CometsComet 17P/HolmesComet 17P/Holmes

BackgroundBackground

HistoryHistory Religious Significance—Religious Significance—

Messenger of Doom/OmenMessenger of Doom/Omen Aristotle (384-322 B.C.)Aristotle (384-322 B.C.) 1577—Tycho Brahe 1577—Tycho Brahe

(1546-1601) (1546-1601)


HistoryHistory Sir Isaac Newton (1643-Sir Isaac Newton (1643-

1727)1727) Edmund Halley (1656-Edmund Halley (1656-

1742)1742) Comet of 1682Comet of 1682


CompositionComposition H, N, O, CHH, N, O, CH44, NH, NH33, CO, CO22, ,

HH22O, Silicates (Varies)O, Silicates (Varies)

StructureStructure NucleusNucleus ComaComa Hydrogen EnvelopeHydrogen Envelope Tail/sTail/s

Gas (Ion) TailGas (Ion) Tail Dust TailDust Tail

Source: www.nasa.gov


Comet NomenclatureComet NomenclatureP/—Periodic Comet ex. 1P/1682 Q1(Halley)P/—Periodic Comet ex. 1P/1682 Q1(Halley)C/—Non-Periodic Comet ex. C/1995 O1(Hale-C/—Non-Periodic Comet ex. C/1995 O1(Hale-

Bopp)Bopp)X/—No Reliable OrbitX/—No Reliable OrbitD/—Broken Up/Lost CometD/—Broken Up/Lost CometA/—Mistakenly Identified CometA/—Mistakenly Identified Comet

Proper Name vs. Formal NameProper Name vs. Formal Name


OrbitOrbitElliptical pathElliptical pathPerihelion vs. Aphelion Perihelion vs. Aphelion

Long-period vs. Short-periodLong-period vs. Short-period


The Solar and The Solar and Heliospheric Heliospheric Observatory (SOHO)Observatory (SOHO)

1,373 Comets1,373 Comets 190 Short Period190 Short Period



Comet P/2007 R5 Comet P/2007 R5 (SOHO)(SOHO)

Comet P/2007 R5 or Comet P/2007 R5


Porous/Active Porous/Active NucleusNucleus

Sunlit SideSunlit Side Intermittent “Activity”Intermittent “Activity” Altering OrbitsAltering Orbits PerturbationsPerturbations


StardustStardust 89P/ Wild 289P/ Wild 2 Predicted Composition vs. Predicted Composition vs.

Observed CompositionObserved Composition


OriginsOriginsKuiper BeltKuiper BeltOort CloudOort Cloud

Source: http://en.wikipedia.org

Observing/Analyzing CometsObserving/Analyzing Comets

Minor Planet Center (MPC)Minor Planet Center (MPC)Desired Observations/Updated OrbitsDesired Observations/Updated OrbitsRight Ascension and DeclinationRight Ascension and DeclinationMagnitude and VelocityMagnitude and Velocity


12inch LX200 (2)12inch LX200 (2) 12inch LX200R (2)12inch LX200R (2) 14inch RCX40014inch RCX400


AstrometricaAstrometrica Input of CoordinatesInput of Coordinates Inspection of Comet and PositionInspection of Comet and PositionGuide Star vs. Manual AdjustmentsGuide Star vs. Manual AdjustmentsTime/Image IntervalsTime/Image Intervals


ProcessingProcessing Dark FieldDark Field Flat FieldFlat Field Stacking Images Stacking Images ““Blinking”Blinking”

C/2006 M4

Observed CometsObserved Comets

P/2007 T2 (Kowalski)P/2007 T2 (Kowalski) Semi-major Axis: 3.11 Semi-major Axis: 3.11

AU AU Eccentricity: 0.77Eccentricity: 0.77 Inclination: 9.92Inclination: 9.92°°


P/2007 R3 (Gibbs)P/2007 R3 (Gibbs) Semi-major Axis: 4.83 Semi-major Axis: 4.83

AUAU Eccentricity: 0.55Eccentricity: 0.55 Inclination: 3.17Inclination: 3.17°°


P/2007 T4 (Gibbs)P/2007 T4 (Gibbs) Semi-major Axis: 5.09 Semi-major Axis: 5.09



C/2007 T5 (Gibbs)C/2007 T5 (Gibbs) Perihelion: 4.19 AUPerihelion: 4.19 AU Eccentricity: 1.0Eccentricity: 1.0 Inclination: 45.26Inclination: 45.26°°


P/2007 T6 (Catalina)P/2007 T6 (Catalina) Semi-major Axis: 4.49 Semi-major Axis: 4.49



C/2007 W1 (Boattini)C/2007 W1 (Boattini) Perihelion: 0.84 AUPerihelion: 0.84 AU Eccentricity: 0.99Eccentricity: 0.99 Inclination: 9.89Inclination: 9.89°°


P/2007 W2 (LINEAR)P/2007 W2 (LINEAR) Semi-major Axis: 4.01 Semi-major Axis: 4.01



C/2007 U1 (LINEAR)C/2007 U1 (LINEAR) Perihelion: 3.33 AUPerihelion: 3.33 AU Eccentricity: 1.00Eccentricity: 1.00 Inclination: 157.79Inclination: 157.79°°

Comet 17P/HolmesComet 17P/Holmes

Source: http://aida.astroinfo.org


November 6, 1892November 6, 1892 Previous OutburstsPrevious Outbursts Dust AvalancheDust Avalanche


Observation Date: October, 29 2007


Observation Date: October 31, 2007


Observation Date: November 2, 2007


Observation Date: November 3, 2007


Source: Seiichi Yoshida


Measuring/Calculating Size of Coma(s)Measuring/Calculating Size of Coma(s)Width of Coma(s) in Pixels:Width of Coma(s) in Pixels:

(X(X22-X-X11))22 + (Y + (Y22-Y-Y11))2 2 = L= L22

Angular Size in Pixels:Angular Size in Pixels:Pixel Resolution(Pixel Resolution("") = (206,265 x Pixel ) = (206,265 x Pixel

Dimension)/Focal LengthDimension)/Focal LengthAngular Size(Angular Size("") = Pixel Resolution x L ) = Pixel Resolution x L


Angular SizeAngular SizePhysical SizePhysical Size Physical Size(km) = (Angular Size x Distance from Physical Size(km) = (Angular Size x Distance from

Earth)/206,265Earth)/206,265 Physical SizePhysical Size→ Relative Size→ Relative Size

Relative Size(km) = Physical Size/12,756 kmRelative Size(km) = Physical Size/12,756 km

Date Physical Size (km) (Outer Coma)

Physical Size (km) (Inner Coma)

Relative Size

26-Oct 233,408.32 0.00 18.29/0.00

29-Oct 576,294.73 182,674.56 45.18/14.32

30-Oct 666,811.32 151,214.46 52.27/11.85

31-Oct 766,252.59 138,923.98 60.07/10.89

2-Nov 917,072.38 138,923.98 71.89/10.89

3-Nov 964,171.41 184,167.57 75.59/14.44

4-Nov 964,171.41 212,334.38 75.59/16.65


Calculating Calculating Expansion VelocityExpansion Velocity

V = V = ∆x/∆t∆x/∆t

Date Velocity (m/s)

10/26-10/29 1,333.61

10-29-10/30 1,079.12

10/30-10/31 966.16

10/31-11/02 968.80

11/02-11/03 566.86

11/03-11/04 0.00


Measuring/Calculating Nuclei SeparationMeasuring/Calculating Nuclei SeparationSeparation of Nuclei in Pixels:Separation of Nuclei in Pixels:

(X(X22-X-X11))22 + (Y + (Y22-Y-Y11))2 2 = L= L22

Angular Distance in Pixels:Angular Distance in Pixels:Pixel Resolution(Pixel Resolution("") = (206,265 x Pixel ) = (206,265 x Pixel

Dimension)/Focal LengthDimension)/Focal LengthAngular Distance(Angular Distance("") = Pixel Resolution x L ) = Pixel Resolution x L


Angular DistanceAngular DistancePhysical DistancePhysical Distance Physical Distance(km) = (Angular Distance x Distance Physical Distance(km) = (Angular Distance x Distance

from Earth)/206,265from Earth)/206,265

Date Physical Distance (km)

26-Oct 10,906.90

29-Oct 36,181.85

30-Oct 51,810.81

31-Oct 55,461.06

2-Nov 81,812.01

3-Nov 97,017.16

4-Nov 103,751.34


Calculating Calculating Separation VelocitySeparation Velocity

V = V = ∆x/∆t∆x/∆t

Date Velocity (m/s)

10/26-10/29 98.30

10-29-10/30 186.33

10/30-10/31 36.47

10/31-11/02 169.24

11/02-11/03 183.00

11/03-11/04 76.11

Special Thanks to Dr. DurigSpecial Thanks to Dr. Durig

Questions?Questions?

comet observation during the advent semester of 2007 matt greenwood

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