Other Solar Systems and Life

Presented By:

ARJEL A. DIONGSON BSEd III-A

Planets Around other Stars

Exoplanet (Extrasolar planet)- a planet outside the solar system.

HISTORY4th Century B.C.

Epicurus – infinite universe with infinite number of worlds.

Aristotle – Earth is unique – center of Universe.

Late 1500s

Copernicus – argues that planets orbit the Sun.

Giordano Bruno – suggests that other stars have planets.

- He was burned at stake.

April 21, 1992

Aleksander Walszczan & Dale

Frail

- radio astronomers who announced the discovery of two planets orbiting the Pulsar PSR 1257+12.

Pulsar – a highly magnetized, rotating neutron star that emits beams of electromagnetic radiation.

October 6, 1995Michel Mayor & Didier Queloz

- announced the first detection of an exoplanet orbiting a main-sequence star Pegasi 51.

51 Pegasi b - first exoplanet discovered approximately 50 light years away in the constellation of Pegasus.

July 2000- 55 confirmed planets around other

stars.

November 2001- 76 confirmed planets around other stars.

November 4, 2013- The Kepler Mission space

telescope detected 3, 568 candidate planets of which about 11% may be false positives.

February 13, 2014- Discovered 1, 035 planets around

774 stars; 179 planetary systems with multiple planets; 3, 841 Kepler candidates and confirmed planets.

February 14, 2014- Discovered 1, 075 planets in

813 planetary systems.

March 1, 2014- 1, 078 confirmed exoplanets

are listed in the Extrasolar Planets Encyclopaedia, including 815 planetary systems of which 179 are multiple planetary systems.

OBSERVATIONS

Large planets ( easier to see)

Orbit relatively close to their

stars.

Orbit more elongated ellipses

than our solar system planets.

Planet- Finding Methods

small, faint object next to large bright objectcould only see very large planets at large orbital distances.Coronagraphs – a telescopic attachment used to block light from the star while leaving the planet visible.

A. Solar CoronagraphB. Stellar Coronagraph

DIRECT OBSERVATION

PHOTOMETRIC OBSERVATION (TRANSIT

METHOD) Brightness of stars dims when

planet passes between Earth and that star.

It can detect planets down to about 2.5x Earth.

a technique in astronomy concerned with measuring the flux, or intensity of an astronomical object’s electromagnetic radiation.

Conducted by gathering radiation in a telescope, perhaps passing it through specialized optical filters, and then capturing and recording the light energy with a photosensitive instrument.

SPECTROSCOPIC OBSERVATION

( RADIAL VELOCITY) Most common technique which

uses Doppler Effect. Doppler Effect ( Doppler Shift) is a

change in frequency of a wave for an observer moving relative to its source, named after Austrian Physicist Christian Doppler.

It examine periodic shifts in the wavelengths in a spectrum.

Arising from wobble of stars as planets orbit the star. ( E.g. Sun wobbles at 12.5 m/s).

Best for massive planets which are close to the star. ( can detect planets down to size of Uranus).

MICROLENSING

An astronomical phenomenon due to gravitational lens effect. It can be used to detect objects ranging from the mass of a planet to the mass of a star, regardless of the light they emit. used the star with the planet as a lens to see distant objects. planet is an “imperfection” in the lens.

INTERFEROMETRIC OBSERVATION

Use infrared light- planet to star

contrast is 1000x better. infrared light – is an electromagnetic radiation with longer wavelengths than those of visible light, extending from the nominal red age of the visible spectrum at 700nm to 1mm.

- use several telescopes ( combine them so that the image of the star is dark).Complicated if there are multiple planets.

PROBLEMS WITH STANDARD MODEL FOR PLANET FORMATION

Big planets are too close to the stars Elongated elliptical orbits

- friction with dust should have circularized the orbits.

NEW MODELS Friction with Dust

- Causes planet’s orbit to decay toward the star Angular Momentum Transfer

- From rapidly spinning star; may stop the inward motion caused by friction Gravitational Scattering

- interactions with protoplanets or very large planets throw some planets in toward the star; Creates elongated orbits.

TITLE PLANET STAR DATA

Farthest OGLE-2005-BLG-390Lb OGLE-2005-BLG-390L 3,300 light yrs

Nearest Alpha Centauri B Alpha Centauri 4.37 light yrs

Least Massive Kepler – 37b Kepler – 37 0.01 M Earth

Biggest Radius CT Cha b CT Cha 2.2 Jupiter Radii

Smallest Radius Kepler – 37b Kepler – 37 0.30 Earth Radii

Most Dense PSR J1719- 1438 b PSR J1719- 1438 ≥ 23,000 kg/m3

Hottest Kepler – 70 b Kepler – 70 7278 K

Highest Albedo Kepler – 10 b Kepler – 10 0.5-0.6

Lowest Albedo TrES – 2b TrES – 2 < 1%

Longest Orbital Period OPH 11b OPH 11 360, 000 Days

Shortest Orbital Period Kepler – 70 b Kepler – 70 5.7768 hours

Highest Metallicity HD 126614 Ab HD 126614 A + 0.56 dex

Lowest Metallicity HIP 13044b HIP 13044 -2.09±0.26 dex

Hottest Star with planet NY Virginis b NY Virginis 33, 247K

Highest Stellar Mass HD 13189 b HD 13189 4.5±2.5 M

Lowest Stellar Mass 2MJ 044144 b 2MJ 044144 0.02 M

PLANETARY SYSTEM CHARACTERISTICS

SYSTEM WITH MOST

( CONFIRMED)PLANETS

HD 10180 9 PLANETS

SYSTEM WITH MOST STARS

KEPLER 64 4 STARS

LIFE IN THE UNIVERSE

HISTORY OF THE UNIVERSE

PLANETS FORMING CLOSE TO SUN

Warmer Strong gravitational forces from Sun (tidal) Hard for light elements to condense from gas to solid ( no water condensed) Hard for solids to collect together

1. planets made of heavy elements only – tend to be smaller; fewer moons because

2. small mass of planets – weaker gravity3. Close to sun – competitions with Sun’s gravity

Cooler Less effects of Sun’s gravity

- light and heavy elements included in planets (also water and ice) – mainly hydrogen

1. By trapping all elements, planets become large and attract even more gas; more moons because

2. Large mass of planets – strong gravity3. Far from Sun – little competition with Sun

PLANETS FARTHER FROM THE SUN

REFERENCES

http://www.bbc.co.uk/science/space/universe/sights/extrasolar_planetshttp://www.springreference.com/docs/html/chapterd/333205.htmlhttp://en.wikipedia.org/wiki/Doppler-effecthttp://www.physicsclassroom.com/class/waves/u10/3d.cfmhttp://www.qrg.northwestern.edu/projects/vss/docs/communications/3.htmlhttp://scienceworld.wolfram.com/physics/gravitationalscattering.htmlhttp://www.universetoday.commobile.nasa.gov/exoplanets