Fraction of stars with planetary systems, fp, 1961 to the present

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Of the Drake Equation’s seven factors, fp, the fraction of stars with planets, is the one on which we have made the most progress. Since 1961, we have gone from ignorance to a fairly reliable determination of what this number is. Our progress has occurred in three phases. In the first, which lasted for more than thirty years after 1961, astronomers were limited to speculation and probabilities, based on the Copernican principle and their growing understanding of processes that led to the formation of our solar system. The second phase began in 1995, when the first exoplanet was discovered using the Doppler method, which kicked a new research field into high gear. Excitement mingled with confusion as hot Jupiter-like planets with highly eccentric orbits were found, planets with unprecedented properties. The next decade and a half saw a steady march of the detection limit from Jupiter mass to Neptune mass and more recently to super-Earths, exoplanets with two-to- five times Earth’s mass. The census grew from a few to over five hundred. The third phase of exoplanet discovery came with the 2009 launch of the Kepler satellite. Astronomers began to use the transit or eclipse method to detect planets smaller than Earth and, as of 2014, they have found more than 3,000 planetary candidates, about 300 of which are similar to or smaller than Earth. Both the Doppler and the transit methods provide information on potential habitability, and taken together they yield a mean exoplanet density. There is remarkable agreement in the exoplanet count derived from three different detection methods: Doppler, transits, and microlensing. With an uncertainty factor of two, there is an exoplanet for every sequence star, and most of them are small, terrestrial, and orbit red dwarfs.

Original languageEnglish (US)
Title of host publicationThe Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages
PublisherCambridge University Press
Pages71-89
Number of pages19
ISBN (Print)9781139683593, 9781107073654
DOIs
StatePublished - Jan 1 2015

Fingerprint

planetary systems
extrasolar planets
stars
transit
planets
Jupiter (planet)
habitability
census
eccentric orbits
Neptune (planet)
confusion
eclipses
solar system
orbits

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Impey, C. D. (2015). Fraction of stars with planetary systems, fp, 1961 to the present. In The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages (pp. 71-89). Cambridge University Press. https://doi.org/10.1017/CBO9781139683593.006

Fraction of stars with planetary systems, fp, 1961 to the present. / Impey, Christopher D.

The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages. Cambridge University Press, 2015. p. 71-89.

Research output: Chapter in Book/Report/Conference proceedingChapter

Impey, CD 2015, Fraction of stars with planetary systems, fp, 1961 to the present. in The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages. Cambridge University Press, pp. 71-89. https://doi.org/10.1017/CBO9781139683593.006
Impey CD. Fraction of stars with planetary systems, fp, 1961 to the present. In The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages. Cambridge University Press. 2015. p. 71-89 https://doi.org/10.1017/CBO9781139683593.006
Impey, Christopher D. / Fraction of stars with planetary systems, fp, 1961 to the present. The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages. Cambridge University Press, 2015. pp. 71-89
@inbook{54f1924951ef4d658286d6d5ba9736dd,
title = "Fraction of stars with planetary systems, fp, 1961 to the present",
abstract = "Of the Drake Equation’s seven factors, fp, the fraction of stars with planets, is the one on which we have made the most progress. Since 1961, we have gone from ignorance to a fairly reliable determination of what this number is. Our progress has occurred in three phases. In the first, which lasted for more than thirty years after 1961, astronomers were limited to speculation and probabilities, based on the Copernican principle and their growing understanding of processes that led to the formation of our solar system. The second phase began in 1995, when the first exoplanet was discovered using the Doppler method, which kicked a new research field into high gear. Excitement mingled with confusion as hot Jupiter-like planets with highly eccentric orbits were found, planets with unprecedented properties. The next decade and a half saw a steady march of the detection limit from Jupiter mass to Neptune mass and more recently to super-Earths, exoplanets with two-to- five times Earth’s mass. The census grew from a few to over five hundred. The third phase of exoplanet discovery came with the 2009 launch of the Kepler satellite. Astronomers began to use the transit or eclipse method to detect planets smaller than Earth and, as of 2014, they have found more than 3,000 planetary candidates, about 300 of which are similar to or smaller than Earth. Both the Doppler and the transit methods provide information on potential habitability, and taken together they yield a mean exoplanet density. There is remarkable agreement in the exoplanet count derived from three different detection methods: Doppler, transits, and microlensing. With an uncertainty factor of two, there is an exoplanet for every sequence star, and most of them are small, terrestrial, and orbit red dwarfs.",
author = "Impey, {Christopher D}",
year = "2015",
month = "1",
day = "1",
doi = "10.1017/CBO9781139683593.006",
language = "English (US)",
isbn = "9781139683593",
pages = "71--89",
booktitle = "The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages",
publisher = "Cambridge University Press",

}

TY - CHAP

T1 - Fraction of stars with planetary systems, fp, 1961 to the present

AU - Impey, Christopher D

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Of the Drake Equation’s seven factors, fp, the fraction of stars with planets, is the one on which we have made the most progress. Since 1961, we have gone from ignorance to a fairly reliable determination of what this number is. Our progress has occurred in three phases. In the first, which lasted for more than thirty years after 1961, astronomers were limited to speculation and probabilities, based on the Copernican principle and their growing understanding of processes that led to the formation of our solar system. The second phase began in 1995, when the first exoplanet was discovered using the Doppler method, which kicked a new research field into high gear. Excitement mingled with confusion as hot Jupiter-like planets with highly eccentric orbits were found, planets with unprecedented properties. The next decade and a half saw a steady march of the detection limit from Jupiter mass to Neptune mass and more recently to super-Earths, exoplanets with two-to- five times Earth’s mass. The census grew from a few to over five hundred. The third phase of exoplanet discovery came with the 2009 launch of the Kepler satellite. Astronomers began to use the transit or eclipse method to detect planets smaller than Earth and, as of 2014, they have found more than 3,000 planetary candidates, about 300 of which are similar to or smaller than Earth. Both the Doppler and the transit methods provide information on potential habitability, and taken together they yield a mean exoplanet density. There is remarkable agreement in the exoplanet count derived from three different detection methods: Doppler, transits, and microlensing. With an uncertainty factor of two, there is an exoplanet for every sequence star, and most of them are small, terrestrial, and orbit red dwarfs.

AB - Of the Drake Equation’s seven factors, fp, the fraction of stars with planets, is the one on which we have made the most progress. Since 1961, we have gone from ignorance to a fairly reliable determination of what this number is. Our progress has occurred in three phases. In the first, which lasted for more than thirty years after 1961, astronomers were limited to speculation and probabilities, based on the Copernican principle and their growing understanding of processes that led to the formation of our solar system. The second phase began in 1995, when the first exoplanet was discovered using the Doppler method, which kicked a new research field into high gear. Excitement mingled with confusion as hot Jupiter-like planets with highly eccentric orbits were found, planets with unprecedented properties. The next decade and a half saw a steady march of the detection limit from Jupiter mass to Neptune mass and more recently to super-Earths, exoplanets with two-to- five times Earth’s mass. The census grew from a few to over five hundred. The third phase of exoplanet discovery came with the 2009 launch of the Kepler satellite. Astronomers began to use the transit or eclipse method to detect planets smaller than Earth and, as of 2014, they have found more than 3,000 planetary candidates, about 300 of which are similar to or smaller than Earth. Both the Doppler and the transit methods provide information on potential habitability, and taken together they yield a mean exoplanet density. There is remarkable agreement in the exoplanet count derived from three different detection methods: Doppler, transits, and microlensing. With an uncertainty factor of two, there is an exoplanet for every sequence star, and most of them are small, terrestrial, and orbit red dwarfs.

UR - http://www.scopus.com/inward/record.url?scp=84954109399&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84954109399&partnerID=8YFLogxK

U2 - 10.1017/CBO9781139683593.006

DO - 10.1017/CBO9781139683593.006

M3 - Chapter

AN - SCOPUS:84954109399

SN - 9781139683593

SN - 9781107073654

SP - 71

EP - 89

BT - The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages

PB - Cambridge University Press

ER -