how to detect planets beyond our solarsystem
DESCRIPTION
gives a brief description of the some of the most popular( and easy to understand) ways of detecting planets that are presently employed by scientist all around the globe.TRANSCRIPT
![Page 1: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/1.jpg)
How to detect How to detect planets beyond planets beyond
our Solar system our Solar system
![Page 2: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/2.jpg)
![Page 3: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/3.jpg)
THE SUN THAT WE KNOWTHE SOLAR SYSTEM
![Page 4: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/4.jpg)
THE NIGHT SKYThe Night Sky
![Page 5: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/5.jpg)
PLANETS derive their name from the term “Wandering Stars”
Planets have been known even to the early cultures. But were viewed as emissaries of god .
![Page 6: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/6.jpg)
Mayan Astronomy
The stone henge
![Page 7: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/7.jpg)
Astronomers star gazing
![Page 8: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/8.jpg)
Intensive telescope search (1930) - based on incorrect prediction!
Predicted by Newtonian Mechanics (1846)
“Naked Eye” planets
Telescope (1781)
![Page 9: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/9.jpg)
Only few planets are visible to the unaided eye , while most remain undetected
Hence astronomers use indirect methods to discover planets beyond our Solar system.
![Page 10: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/10.jpg)
THE METHODS INCLUDE:
a.Transit method.
a.Radial velocity method.
a.Pulsar timing.
![Page 11: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/11.jpg)
![Page 12: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/12.jpg)
TRANSIT METHODTRANSIT METHODOne of the simplest methods
Uses fundamental concepts like:
i.Concept of eclipseii.Variation in luminous intensity during
eclipseiii.Parallax method.
![Page 13: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/13.jpg)
![Page 14: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/14.jpg)
Understanding transiting motionUnderstanding transiting motion
The luminous intensity of the star observed by us changes when planet transits before the parent star.
![Page 15: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/15.jpg)
Variation in the intensity α The size of planet.
Luminous intensity of star HD209458 dims by 1.7%
![Page 16: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/16.jpg)
![Page 17: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/17.jpg)
![Page 18: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/18.jpg)
Applications of transit Applications of transit methodmethod
1.Determining the radius of the planet.
Makes use of light curve and parallax method
![Page 19: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/19.jpg)
2. Study of planets upper atmosphere.
• Light emanating from the upper atmosphere is studied under high resolution stellar spectrum.
• Thus detecting elements in the atmosphere.
![Page 20: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/20.jpg)
![Page 21: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/21.jpg)
![Page 22: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/22.jpg)
•3. Temperature of the planet
• Observed during secondary eclipse(when planet behind the star).
• Original light signal of star is obtained.
![Page 23: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/23.jpg)
Light intensity of planet = a-b a= light intensity during secondary eclipse
b= intensity with planet transiting the star
![Page 24: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/24.jpg)
The reading estimates the temperature and
Possibility of cloud formation.
![Page 25: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/25.jpg)
Temperatures of various planets found using Transit method
![Page 26: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/26.jpg)
Could this indicate presence of life.......................?
............Well the research is going on
![Page 27: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/27.jpg)
ADDITIONAL INFORMATIONADDITIONAL INFORMATIONTemperature of some exoplanets:
TrES-1 = 1060k.
HD209458 = 1130k.
![Page 28: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/28.jpg)
DISADVANTAGES OF DISADVANTAGES OF TRANSIT METHODTRANSIT METHOD
1.Planets need to be aligned with the astronomer’s vantage point.
![Page 29: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/29.jpg)
Only about 10% of planets with small orbits have these alignment and this percentage decreases with size of the planet.
Probability of random alignment producing transit is mere 0.47%
![Page 30: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/30.jpg)
This method suffers from high rate of false detection.
Hence transit method requires additional conformation
AND…….. radial velocity method provides this !
![Page 31: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/31.jpg)
THE RADIAL VELOCITY METHOD
![Page 32: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/32.jpg)
RADIAL VELOCITY METHODRADIAL VELOCITY METHOD• Radial velocity method too makes use of basic concepts such as :
1.Centre of mass.2.Spectral lines.3.Radial velocity.4.Dopplers effect.
![Page 33: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/33.jpg)
![Page 34: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/34.jpg)
• The motion of the planet and star system
![Page 35: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/35.jpg)
![Page 36: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/36.jpg)
A system of parent star and it’s planets is studied , with planet moving around the star.
Parent star wobbles(spins around the common cm)
![Page 37: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/37.jpg)
During primary eclipse star moves towards us .
During secondary eclipse the planet tugs the star away from earth.
![Page 38: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/38.jpg)
Starlight so obtained during this motion is studied under a spectrograph.
The absorption lines so obtained exhibit variation in the radial velocity of the star
![Page 39: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/39.jpg)
![Page 40: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/40.jpg)
These stellar spectral lines shift
towards the red end of spectrum as star moves away from earth
And towards the blue end of spectrum as it moves towards the earth
![Page 41: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/41.jpg)
Variation in the radial velocity being measured
![Page 42: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/42.jpg)
An actual observatory
![Page 43: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/43.jpg)
The variation in the velocity up to 1m/s can be measured with modern spectrometers example: HARPS,HIRES etc.
![Page 44: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/44.jpg)
HIRESHIRES
![Page 45: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/45.jpg)
Radial velocity method has been the most productive technique used by planet hunters.
This method determines minium mass of the planet.
![Page 46: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/46.jpg)
LIMITATIONSLIMITATIONSOnly sensitive towards large
Jupiter sized planets.
Insensitive towards rocky planets. Large investment of time & resources
![Page 47: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/47.jpg)
Few planets discovered using radial velocity method
![Page 48: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/48.jpg)
THE PULSAR TIMING
![Page 49: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/49.jpg)
• Pulsars are dense remnant of stars that exploded as supernova.
• Pulsars emit electromagnet radiations at regular intervals.
![Page 50: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/50.jpg)
•
Slight anomaly in the timing of the radio pulsars is. used to track the pulsar’s motion This forms the basis of pulsar timing.
![Page 51: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/51.jpg)
Working of the pulsar motion
![Page 52: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/52.jpg)
• Pulsar timing is very sensitive method
• Can detect planets as small as a 10th of the earth’s mass.
![Page 53: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/53.jpg)
![Page 54: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/54.jpg)
LimitationsLimitations• Pulsars are rare to find in the
universe hence it’s to detect planets is restricted
• The surrounding of pulsars contains intense em radiation, which is unsuitable for life forms.
![Page 55: How to detect planets beyond our solarsystem](https://reader033.vdocuments.us/reader033/viewer/2022061120/546cd807af795953298b5060/html5/thumbnails/55.jpg)