Exoplanet Detection Techniques

have yet been detected on any of the nearly 2,000 scientifically confirmed exoplanets. So we

We cannot get close enough to observe with our own eyes, so there are different techniques that can be utilized to garner this information. This part of the equation is characterized as Fp, Fp is the fraction of stars that actually have planets. One method used in the study of potential solar systems is the transit method. This is the dimming of a star which can show a planet passing in front, which in turn proves that a planetary system exists around that star. This example is much like the experiment we did in class that showed the planets passing around the yellow sphere that was lit up inside.

Michel Mayor and Didier Queloz established another milestone, recording 51 Pegasi b, also known as Bellerophon, as the first established exoplanet in 1995. Located about 50 million light years away in the constellation Pegasus, Bellerophon is known as the first planet outside our solar system that orbits a star similar to our sun with the help of spectroscopy. Spectroscopy is described as the study of communication amongst matter and electromagnetic radiation. It used to consider visible light scattered according to its wavelength by a prism, but later the idea was developed to contain any contact with radiative energy as a function of its wavelength or frequency. Technological advances, most notably in high-resolution spectroscopy, led to

This experiment was conducted to study and investigate if extraterrestrial life exists upon the exoplanet TRES 2. It was hypnotized that TRES 2 did not sustain the qualifications to support extraterrestrial existence. The results from this testing conclude the hypothesis was correct, with research as an addition from the luminosity testing it has been knowledge that TRES 2 reflects less than 1% of light making it one of the darkest exoplanets currently discovered. Light is a crucial element in the building blocks of life, it is the most important factor that influence the way life evolved on Earth. From photosynthesis, which is responsible for making producing nutrients in plantae’s and meeting our energy requirements. Furthermore TRES 2 orbits

The foreground planet would help us detect formation, evolution and the dynamics of a planetary system. This event is due to the position of a planet in respect to its parent star, if the foreground planet is smaller than the background star it is known as a transit, instead of an occultation. An example would be the occultation of Regulus by

Exoplanet classification is facilitated by the fact that a distinction in mass between planets and smaller bodies is not yet relevant. In contrast, nomenclature is complicated by the problems of distinguishing planets from brown dwarfs. The IAU 2003 recommendation, by the working group on extrasolar planets (IAU, 2003) is:

On April 18th, 2013, NASA’s Kepler satellite had detected an exoplanet in the Kepler-62 star system, Kepler-62e, one of the farthest exoplanets from its parent system within Kepler-62’s orbit. Using transit photometry, NASA could find a total of 5 exoplanets orbiting this star, including Kepler-62e. With a mass of around 36 earth masses and a radius 60 percent larger than Earth’s, Kepler-62e was a rather easy discovery using transit photometry. Transit photometry involves calculating the magnitude of a star over time; watching for deviations in the star’s magnitude to differentiate whether the deviation is normal or increased. For the record, any detected star system receives the designation “Kepler” in lieu of the Kepler satellite which detects them; planets are given the same name with the exception of a letter added onto the end.

The Kepler spacecraft searches for transits, but ground-based Doppler spectroscopy and space-based astrometry are used to search for companion stars in planetary systems in order to gain a better understanding of their structure (NASA). The transit method requires an alignment of the planet’s orbit with the spacecraft, so that the planet will block a portion of its star’s light when a transit occurs. The dip in a planet’s brightness, that a photometer records, is directly proportional to the planet’s size. Furthermore, the atmosphere of the planet will absorb the star’s light at certain wavelengths. The light absorbed by the planet’s atmosphere is recorded by the photometer. Then, scientists can determine what molecules are in the atmosphere based on how much light is absorbed (Hall). Many details can be gathered from the transit; however, there are drawbacks to the transit method. NASA stated on Kepler’s webpage that, “The probability for an orbit to be properly aligned is equal to the diameter of the star divided by the diameter of the orbit. This is 0.5% for a planet in an Earth-like orbit about a Sun-like star” (NASA). In order to compensate for this deficiency in the transit method, Kepler observes over 100,000

Clearly the better and stronger our telescopes and other methods used to evaluate the sky will result in further discoveries. Not only do we have Earth bound telescopes; we have telescopes in the sky that can get even closer to other matter – whether that be planets, stars, comets, asteroids, etc. The textbook also notes radial velocity and how the gravitational pull of a planet results in the star wobbling. “If the wobble happens to occur along our line of sight to the star, then we see small fluctuations in the star’s radial velocity, which can be measured using the Doppler effect” (Chaisson & McMillan, 2014, p 371) allowing us to estimate the mass of the planet (Chaisson & McMillan, 2014, p 371). I found this website: http://www.planetary.org/explore/space-topics/exoplanets/how-to-search-for-exoplanets.html that gives three ways. They are noted as radial velocity (already stated); transit photometry (having to do with the brightness – or lack thereof – of a star when another “planet passes between it and the Earth” (How to Search for Exoplanets)), and Microlensing (stated as the only real method that is capable of discovering other planets at huge distances from Earth (How to Search for Exoplanets)). It further notes that while radial velocity can identify them within 100 light years, transit photometry can identify them more than 100 light years (100’s in fact), and transit photometry can find those that are thousands of light years away. I need to understand

As we know that super-Earth doesn’t mean Earth like planet, it can be much better. They’re extrasolar planets whose mass is greater than Earth’s, yet much lesser than our solar system’s ice giants Neptune and Uranus, which have a very high mass that it can easily fit 17 and 15 Earths, respectively (note that Uranus is bigger than Neptune but it is less massive). Since the category only speaks to the exoplanet’s mass, we can’t say anything about an exoplanet’s surface conditions. It’s big, but may or may not be suitable to sustain

Astronomers began looking for another way to find new planets and cosmos. They needed new equipment and stated Using several South American, African, and Australian telescopes. When scientists started using new telescopes, they were able to detect bigger planets that are farther away from their stars, like Jupiter or Saturn. However, this method does not reveal smaller planets that are close to their stars. Scientist needed another way to find stars so they began to use NASA's Kepler telescope. NASA's Kepler telescope can detect planets as small as Earth. So far astronomers have discovered that there are probably 2 or more planets per star.

B1 (done) : Exoplanets are a unique type of planets because it orbits stars other than the sun, they are made mostly of diamond and graphite. Exoplanets are known to be beyond our solar system,

The constant search for new life and curiosity of planets in solar systems beyond our own is another topic Hubble has researched. Planets are difficult to detect because their faint light is outshined by neighboring stars. True planets reflect a fraction of the light exerted upon them by the star, so they are very dim in comparison. Using a method called the “radial velocity method”, Hubble has detected hundreds of exoplanets, most of which are larger than Jupiter. As radial velocity gets more accurate, Hubble could detect “super-Earths”, which are smaller. This method can only provide information of the planet’s mass and orbit, so Hubble uses the another method to gather more detailed information on these alien worlds. The transit method is

The radial velocity method was used to detect the first exoplanet, 51 Pegasi b (51 Peg b) around a main sequence star, 51 Pegasi (51 Peg). The radial velocity method uses the variations in velocity of a star due to the gravitational pull from an exoplanet (Lissauer 2002). Furthermore the velocity isn’t measured in terms of actual speed but in terms of light based on the Doppler effect. The Doppler effect occurs when a star moves. When it moves toward us, its wavelengths of light are shortened and when a star moves away from us, its wavelengths of light are lengthened. Through the continued observation of the Doppler effect on a stars spectrum of light, the velocity of a star is inferred. Any change in a stars velocity is caused by a sufficiently massive companion, an exoplanet (Lissaeur 2002).

Ancient astronomers were able to differentiate between stars and planets, as stars remain relatively fixed over the centuries while planets will move an appreciable amount during a comparatively short time.