University of Hertfordshire

From the same journal

From the same journal

By the same authors

A long-period planet orbiting a nearby Sun-like star

Research output: Contribution to journalArticlepeer-review


  • H.R.A. Jones
  • R.P. Butler
  • C.G. Tinney
  • S. O'Toole
  • R. Wittenmyer
  • G.W. Henry
  • S. Meschiari
  • S. Vogt
  • E. Rivera
  • G. Laughlin
  • B.D. Carter
  • J. Bailey
  • J.S. Jenkins
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Original languageEnglish
Pages (from-to)1703-1713
JournalMonthly Notices of the Royal Astronomical Society
Publication statusPublished - 2010


The Doppler wobble induced by the extra-solar planet HD 134987b was first detected by data from the Keck Telescope nearly a decade ago, and was subsequently confirmed by data from the Anglo-Australian Telescope (AAT). However, as more data have been acquired for this star over the years since, the quality of a single Keplerian fit to that data has been getting steadily worse. The best-fitting single Keplerian to the 138 Keck and AAT observations now in hand has an root-mean-square (rms) scatter of 6.6 m s−1. This is significantly in excess of both the instrumental precision achieved by both the Keck and Anglo-Australian Planet Searches for stars of this magnitude, and of the jitter expected for a star with the properties of HD134987. However, a double Keplerian (i.e. dual planet) fit delivers a significantly reduced rms of 3.3 m s−1. The best-fitting double planet solution has minimum planet masses of 1.59 and 0.82 1.59 ± 0.02MJup, orbital periods of 258 and 5000 d, and eccentricities of 0.23 and 0.12, respectively. We find evidence that activity-induced jitter is a significant factor in our fits and do not find evidence for asteroseismological p modes. We also present seven years of photometry at a typical precision of 0.003 mag with the T8 0.8 m automatic photometric telescope at Fairborn observatory. These observations do not detect photometric variability and support the inference that the detected radial-velocity periods are due to planetary mass companions rather than due to photospheric spots and plages.


Original article can be found at: Copyright Royal Astronomical Society

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