Five Planets Orbiting 55 Cancri

By Debra A. Fischer, G. Marcy, R. P. Butler, S. Vogt, Gregory Laughlin, G. Henry, David Abouav, K. Peek, Jason T. Wright, John A. Johnson and 2 more. 2007

217 citations recorded by the source corpus.

We report 18 years of Doppler shift measurements of a nearby star, 55 Cancri, that exhibits strong evidence for five orbiting planets. The four previously reported planets are strongly confirmed here. A fifth planet is presented, with an apparent orbital period of 260 days, placing it 0.78 AU from the star in the large empty zone between two other planets. The velocity wobble amplitude of 4.9 m s−1 implies a minimum planet mass Msin i = 45.7 M⊕. The orbital eccentricity is consistent with a circular orbit, but modest eccentricity solutions give similar χ2ν fits. All five planets reside in low-eccentricity orbits, four having eccentricities under 0.1. The outermost planet orbits 5.8 AU from the star and has a minimum mass Msin i = 3.8 MJup, making it more massive than the inner four planets combined. Its orbital distance is the largest for an exoplanet with a well-defined orbit. The innermost planet has a semimajor axis of only 0.038 AU and has a minimum mass, Msin i, of only 10.8 M⊕, making it one of the lowest mass exoplanets known. The five known planets within 6 AU define a minimum-mass protoplanetary nebula to compare with the classical minimum-mass solar nebula. Numerical N-body simulations show this system of five planets to be dynamically stable and show that the planets with periods of 14.65 and 44.3 days are not in a mean motion resonance. Millimagnitude photometry during 11 years reveals no brightness variations at any of the radial velocity periods, providing support for their interpretation as planetary.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/474bb4bdc8874b5990b9f24b096c516d1cc0e734

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In Astronomy and Astrophysics

1. N. Madhusudhan
2. J. Johnson
3. Andrew W. Howard
4. J. Winn
5. G. Marcy
6. M. Perryman
7. Jon Fortney
8. D. Charbonneau

Citations in the corpus

• A SUPER-EARTH TRANSITING A NAKED-EYE STAR (2011, background): “Transits of b and c were ruled out by Fischer et al. (2008).11 However, the nondetections do not lead to constraints on mutual inclinations.”
• Debris disks as signposts of terrestrial planet formation (2011, background): “Second, there exist individual systems that show no obvious signs of instability, for example with planets in resonance (e.g., GJ 876; Rivera et al. 2010) or with many relatively closelypacked giant planets (e.g., 55 Cancri; Fischer et al. 2008).”
• DETECTION OF AN ATMOSPHERE AROUND THE SUPER-EARTH 55 CANCRI E (2015, background): “At a distance of only 12 pc, 55 Cancri is an extremely interesting planetary system hosting five planets, all discovered via radial velocity measurements (Butler et al. 1997; Marcy et al. 2002; McArthur et al. 2004; Fischer et al. 2008).”
• EFFICIENT FITTING OF MULTIPLANET KEPLERIAN MODELS TO RADIAL VELOCITY AND ASTROMETRY DATA (2009, methodology): “To quantify this improvement, we tested two cases with published RV data, the 2-planet system HD 217107 (Vogt et al. 2005) and the 5-planet system 55 Cnc (Fischer et al. 2008) (in both cases assuming no jitter).”
• A POSSIBLE CARBON-RICH INTERIOR IN SUPER-EARTH 55 Cancri e (2012, background): “The planet was originally discovered in a five-planet system by the radial velocity method which gave its minimum mass (McArthur et al. 2004; Fischer et al. 2008).”
• RADIAL VELOCITY PLANETS DE-ALIASED: A NEW, SHORT PERIOD FOR SUPER-EARTH 55 Cnc e (2010, methodology): “We find that the period of 2.817 days reported in the literature for planet e (McArthur et al. 2004; Fischer et al. 2008) is actually a daily alias of its true period of 0.737 days.”
• TEN NEW AND UPDATED MULTIPLANET SYSTEMS AND A SURVEY OF EXOPLANETARY SYSTEMS (2008, background): “In the short term, these interactions can cause detectable variations in the orbits of the planets (Rivera et al. 2005; Fischer et al. 2008).”
• THE CALIFORNIA PLANET SURVEY. I. FOUR NEW GIANT EXOPLANETS (2010, unknown): “The other such planets—55Cncd (Fischer et al. 2008), HD217107c (Vogt et al. 2005; Wright et al. 2009) and HD187123c (Wright et al. 2007, 2009)—are all in multi-planet systems.”
• ORBITAL MOTION OF HR 8799 b, c, d USING HUBBLE SPACE TELESCOPE DATA FROM 1998: CONSTRAINTS ON INCLINATION, ECCENTRICITY, AND STABILITY (2011, background): “These include discoveries using radial velocities (Fischer et al. 2008; Rivera et al. 2010), transits (Holman et al. 2010; Lissauer et al. 2011a,b), microlensing (Gaudi et al. 2008), and pulsar timing (Wolszczan 1994).”
• Detection of a transit of the super-Earth 55 Cancri e with warm Spitzer (2011, background): “As shown by these authors, the orbital period value initially reported for this planet, 2.8 days (McArthur et al. 2004; Fischer et al. 2008), was an alias of the true period, 0.74 day.”
•  ?> -REx. II. RETRIEVAL OF EMISSION SPECTRA (2015, methodology): “We simulated an emission spectrum of the hot SuperEarth 55 Cnc e (Fischer et al. 2008).”
• THE TWENTY-FIVE YEAR LICK PLANET SEARCH (2013, unknown): “…multi-planet system around a normal star, Ups And b, c, d (Butler et al. 1997, 1999), 55 Cnc b, c, d, f, g (Butler et al. 1997; Marcy et al. 2002; Fischer et al. 2008), HD 195019 b and HD 217107 b (Fischer et al. 1999), HD 89744 b (Korzennik et al. 2000), GJ 876 b, c, d (Marcy et al. 2001;…”
• POSSIBLE DISINTEGRATING SHORT-PERIOD SUPER-MERCURY ORBITING KIC 12557548 (2012, background): “E P] 2 4 M ar 2 01 2 measurements (Fischer et al. 2008; Dawson & Fabrycky 2010) and detected in transit by extensive satellite observations with the MOST satellite (Winn et al. 2011).”