Welcome to the AAPS

 

News

  1. 19 December 2012 - "Periodic variations in the tau Ceti velocities" (A&A in press)


    1. - Paper now available on
      astro-ph.
      -
      UNSW Press Release
      -
      UK Press Release
      -
      UK Press Release Materials & Images

      Coverage


    2. -
      New Scientist
      -
      Space.com
      - The Guardian
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      ABC Online
      - ABC PM (Cached audio)
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      The Australian, Daily Telegraph
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      COSMOS
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      AFP

    14 Nov 2012 - AAPS had a good night at the 2012 NSW Science and Engineering Awards last night - Chris Tinney winning an Excellence award in Physics, Maths, Chemistry & Astronomy, as a reflection of the excellent work done by everyone in the AAPS team over the last 5 years!


    1 May 2011 - AAPS Discovers Two New Planets
                   .... and asks "What do we really know about habitable exomoons?"


    1. Two papers have recently been published presenting new planets from the Anglo-Australian Planet Search. The first (HD102365b) is a Neptune mass planet in a 122d orbit - and this planet (unlike many of the other Neptune-mass and smaller planets recently discovered) orbits its star in splendid and lonely isolation.

      The second planet (HD38283b) has an orbital period of almost exactly one year - prompting us to ask just what we do know about the formation and habitability of the possible moons of such a planet.


    31 January 2011 - AAPS Simulations measure prevalence of Jupiter Analogs

    1. The detailed simulation of over a decade's worth of AAPS observations have revealed that only ~3% of our target stars have been revealed to host "Jupiter analogs" (ie. gas-giant planets in long-period orbits). And that at most ~30% could possibly be hiding such planets









Links

  1. Planets Discovered by AAPS

  2. AAPS Target Stars

  3. Observing with the SuperAAPS GUI

  4. Notes for AAPS CaHK Observing

  5. UCLES Iodine Cell gets Automated

  6. AAO CCD Non-linearities


    Page last updated 18 March 2013




How our planet search works.


  1. Every planets exert a small gravitational pull on its parent star, causing the star to wobble. In particular, its velocity will be continually varying as it repeatedly moves away from, and then back towards, the Earth. Such velocity changes can be detected via the Doppler Effect.


  2. When the unseen planet is moving away from the Earth, the star will move towards the Earth. The light emitted by a star when it is doing this is Doppler shifted to shorter (bluer) wavelengths. The reverse happens when the unseen planet is moving toward the Earth - the star moves away, and the light it emits is shifted to longer (redder) wavelengths.


  3. The velocity changes revealed by this Doppler wobble depend on the distance at which the planet orbits, the mass of the planet, and how circular its orbit is. For typical gas-giant planets the Doppler velocity variations are in the range 1 to 100 m/s. Because of the small velocities involved, the effect is subtle - it doesn't effect the
    apparent colour of the star, for example. But it can be detected by very high precision astronomical instruments like the UCLES spectrograph on the AAT.


  1. So stars with planets can be identified via the observation of periodic Doppler shifts in their light. After one or two orbital periods the information from the Doppler measurements allows us to calculate the orbit and mass of the unseen planet. Our current measurement precision is 1 meter per second (a slow walk). For comparison, Jupiter causes the Sun to wobble with a velocity of 12.5 meters per second over a 12 year period. Saturn induces a 2.7 meter per second wobble on the Sun with a 30 year period.  



The AAPS Project


  1. AAPS has been operating since January 1998, and is expected to run until at least 2010, at which point we will have observed for long enough to detect Jupiter-like planets in Jupiter-like orbits around other stars. We are currently monitoring around 240 of the nearest and brightest Sun-like stars visible from the AAT's Southern Hemisphere location on 32 nights per year. (In addition we are also carrying out intensive campaign-mode observations on 48 nights per year, of smaller sets of the most stable stars in our main sample, in an effort to find small planets of masses down to a few times the mass of the Earth).


  2. We perform these observations using the University College London Echelle Spectrograph (UCLES). UCLES enables us to observe almost the entire visible spectrum in a single observation. Doppler shifts in the stellar spectra are measured with reference to a precision calibrated iodine vapour absorption cell (like that shown above). The absorption that produces the faint purple colour of the iodine gas in this cell, imprints a dense network of narrow lines on our spectra, telling us everything we need to know about UCLES's performance.


  3. The only example of a star with planets that know in much detail is our own Solar System. Ultimately we need to know what fraction of Sun-like stars have Jupiter- and Saturn-mass planets in Jupiter- and Saturn-like orbits. In other words,  what fraction of extra-solar planetary systems are similar to our own?







Team Members & Contact Details (in alphabetical order)

  1. Jeremy Bailey, University of New South Wales (j.bailey -at- unsw.edu.au)

  2. Paul Butler, Carnegie Institution of Washington (paul - at- dtm.ciw.edu)

  3. Brad Carter, University of Southern Queensland (carterb - at- usq.edu.au)

  4. James Jenkins, University of Hertfordshire (j.s.jenkins -at- herts.ac.uk)

  5. Hugh Jones, University of Hertfordshire (h.r.a.jones -at- herts.ac.uk)

  6. Simon O'Toole, Anglo-Australian Observatory (otoole -at- aao.gov.au)

  7. Chris Tinney, University of New South Wales (cgt -at- phys.unsw.edu.au)

  8. Rob Wittenmyer, University of New South Wales (rob -at- phys.unsw.edu.au)




Contact Information for the Anglo-Australian Telescope

  1. AAT Control Room +61 2 48 42 6279

  2. AAT Geodetic coordinates:

  3. Longitude = 149:03:57.91 = 9h56m15.861 East

  4. Lattitude = 31:16:37.34 South

  5. Altitude = 1164 m




AAPS Publications


  1. Planet Detection Papers


  2. I - First Results from the Anglo-Australian Planet Search: A Brown Dwarf Candidate and a  51 Peg-like Planet.
    Tinney et al. 2001, ApJ, 551, 507. ADS Abstract and Links

  3. II - Two New Planets from the Anglo-Australian Planet Search. 
    Butler et al. 2001, ApJ, 555, 410. ADS Abstract and Links

  4. III -Two Extrasolar Planets from the Anglo-Australian Planet Search
    Tinney et al. 2002, ApJ, 571, 528. ADS Abstract and Links

  5. IV -A probable planetary companion to HD 39091 from the Anglo-Australian Planet Search
    Jones et al. 2002, MNRAS, 333, 871. ADS Abstract and Links

  6. V -On the Double Planet System Around HD 83443
    Butler et al. 2002, ApJ, 578, 565. ADS Abstract and Links

  7. VI - Extra-solar planets around HD 196050, HD 216437 and HD 160691
    Jones et al. 2003, MNRAS, 337, 1170. ADS Abstract and links

  8. VII - Four new planets around metal-enriched stars
    Tinney et al. 2003, ApJ, 587, 423. ADS Abstract and links

  9. VIII - An exoplanet in orbit around τ1 Gruis
    Jones et al. 2003, MNRAS, 341, 948. ADS Abstract and Links

  10. IX - A Planet in a Circular Orbit with a 6 Year Period
    Carter et al. 2003. ApJ, 593, L43. ADS Abstract and Links

  11. X - Multiple Companions to HD 154857 & HD 160691
    McCarthy et al. 2004, ApJ, 617, 575. ADS Abstract and Links

  12. XI - Three low-mass planets from the Anglo-Australian Planet Search
    Tinney et al. 2005, ApJ, 623, 1171. ADS Abstract and Links

  13. XII - High-eccentricity planets from the Anglo-Australian Planet Search
    Jones et al. 2006, MNRAS, 369, 249. ADS Abstract and Links

  14. XIII - The 2:1 Resonant Exoplanetary System Orbiting HD 73526
    Tinney et al. 2006, ApJ, 647, 594. ADS Abstract and Links

  15. XIV - Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars.
    Wright et al. ApJ, 2007. 657, 533. ADS Abstract and Links

  16. XV - New Planets around Three G Dwarfs
    O'Toole et al. 2007, ApJ, 660, 1636. ADS Abstract and Links

  17. XVI - A Jupiter-like Planet Orbiting the Nearby M Dwarf GJ832
    Bailey et al. 2009, ApJ, 690, 743. ADS Abstract and Links

  18. XVII - A Neptune-mass Planet Orbiting the Nearby G Dwarf HD16417
    O'Toole et al. 2009, ApJ, in press. Abstract and Links.

  19. XVIII - A Super-Earth and two Neptunes Orbiting the Nearby Sun-like star 61 Virginis
    Vogt et al. 2010, The Astrophysical Journal, ApJ, 708, 1366. Abstract and Links

  20. XIX - A long-period planet orbiting a nearby Sun-like star
    Jones et al. 2010, Monthly Notices of the Royal Astronomical Society, 403, 1703. Abstract and Links

  21. XX - The Anglo-Australian Planet Search. XX. A Solitary Ice-giant Planet Orbiting HD 102365
    Tinney et al. 2011, ApJ, 727, 103. ADS Abstract and Links

  22. XXI - The Anglo-Australian Planet Search. XXI. A Gas-giant Planet in a One Year Orbit and the Habitability of Gas-giant Satellites
    Tinney et al. 2011, ApJ, 732, 21. ADS Abstract and Links

  23. XXII - The Anglo-Australian Planet Search. XXII. Two New Multi-Planet Systems
    Wittenmyer et al. 2012, ApJ, 753, 169. ADS Abstract and Links


  24. Other AAPS papers


  25. 1. Echelle spectroscopy of Ca II HK activity in Southern Hemisphere planet search targets.
    Tinney et al. 2002, MNRAS, 332, 759. ADS Abstract and Links

  26. 2. Constraining the difference in convective blueshift between the components of alpha Cen with precise radial velocities
    Pourbaix et al. 2002, A&A, 386, 280. ADS Abstract and Links

  27. 3. Observed Properties of Exoplanets: Masses, Orbits, and Metallicities
    Marcy et al. et al. 2005, Prog.Ther.Phys, 158, 24. ADS Abstract and Links

  28. 4. Catalog of Nearby Exoplanets
    Butler et al. 2006, ApJ, 646, 505. ADS Abstract and Links

  29. 5. The abundance distribution of stars with planets
    Bond et al. 2006, MNRAS, 370, 163. ADS Abstract and Links

  30. 6. An activity catalogue of southern stars
    Jenkins et al. 2006, ApJ, 372, 163. ADS Abstract and Links

  31. 7. Exoplanet properties from Lick, Keck and AAT
    Marcy G.W. et al., 2008, Physica Scripta, 130, 14001. ADS Abstract and Links

  32. 8. The impact of stellar oscillations on Doppler velocity planet searches
    O'Toole, S. J., Tinney, C. G. & Jones, H. R. A., MNRAS, 2008, 386. ADS Abstract and Links

  33. 9. Beyond the Iron Peak: r- and s-process Elemental Abundances in Stars with Planets
    Bond J.C. et al. 2008, ApJ, 682, 1234. ADS Abstract and Links

  34. 10. Selection Functions in Doppler Planet Searches
    O'Toole et al. 2009, MNRAS, 392, 641. ADS Abstract and Links

  35. 11. The Frequency of Low-Mass Exoplanets
    O'Toole et al. 2009, ApJ, 701, 1732. Abstract and Links

  36. 12. NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys
    Jenkins et al. 2010, Astronomy & Astrophysics, 515, 17. ADS Abstract and Links

  37. 13. The Frequency of Low-mass Exoplanets. II. The "Period Valley"
    Wittenmyer et al. 2010, ApJ, 722, 1854. ADS Abstract and Links

  38. 14. On the Frequency of Jupiter Analogs
    Wittenmyer et al. 2010, ApJ, 727, 102. ADS Abstract and Links

  39. 15. The Frequency of Low-Mass Exoplanets. III. Toward eta-Earth at Short Periods
    Wittenmyer et al. 2011, ApJ, 738. ADS Abstract and Links.

  40. 16. A dynamical analysis of the proposed HU Aquarii planetary system
    J. Horner, J. P. Marshall, Robert A. Wittenmyer, C. G. Tinney
    Monthly Notices of the Royal Astronomical Society, 2011, 416, L11
    Abstract and Links

  41. 17.Revisiting the proposed planetary system orbiting the eclipsing polar HU Acquarii
    Robert A. Wittenmyer, J. Horner, J. P. Marshall, O.W. Butters, C. G. Tinney
    Monthly Notices of the Royal Astronomical Society Letters, 419, 3258
    Abstract and Links

  42. 18.A Detailed Investigation of the Proposed NN Serpentis Planetary System
    J. Horner, R. A. Wittenmyer, T. C. Hinse & C. G. Tinney
    Monthly Notices of the Royal Astronomical Society, 425, 749
    Abstract and Links

  43. 19.A Dynamical Analysis of the Proposed Circumbinary HW Virginis Planetary System
    J. Horner, T. C. Hinse, R. A. Wittenmyer, J. P. Marshall, C. G. Tinney
    Monthly Notices of the Royal Astronomical Society, in press (accepted 1 Sep 2012)
    Abstract and Links

  44. 20.Signals embedded in the radial velocity noise. Periodic variations in the tau Ceti velocities
    Mikko Tuomi, Hugh R. A. Jones, James S. Jenkins, Chris G. Tinney, R. Paul Butler, Steve S. Vogt, John R. Barnes, Robert A. Wittenmyer, Simon O'Toole, Jonathan Horner, Jeremy Bailey, Brad D. Carter, Duncan J. Wright, Graeme S. Salter, David Pinfield
    Astronomy & Astrophysics, 551, 79
    Abstract and Links

  45. 21. Observing Strategies for the Detection of Jupiter Analogs
    Wittenmyer, Robert A.; Horner, J.; Butler, R. P.; Jones, H. R. A.; O'Toole, S. J.; Bailey, J.; Carter, B. D.; Salter, G. S.; Wright, D.
    Publications of the Astronomical Society of the Pacific, 125, 351
    ADS Abstract and Links

  46. 22. Forever alone? Testing single eccentric planetary systems for multiple companions
    Wittenmyer, Robert A., Wang, Songhu, Horner, Jonathan, Tinney, C. G., Butler, R. P., Jones, H. R. A., O'Toole, S. J., Bailey, J., Carter, B. D., Salter, G. S., Wright, D., Zhou, Ji-Lin
    The Astrophysical Journal Supplement, 208, 2
    ADS Abstract and Links


  47. Astroseismology Papers using the AAPS Radial Velocity System


  48. 1. Evidence for Solar-like Oscillations in β Hydri
    Bedding et al. 2001, ApJ, 549, L105. ADS Abstract and Links

  49. 2. Solar-like oscillations in β Hydri: Confirmation of a stellar origin for the excess power
    Carrier et al. 2001, A&A, 378, 142. ADS Abstract and Links.

  50. 3.Ultra-High Precision Velocity Measurements of Oscillations in α Centauri A
    Butler, R.P. et al., 2004, ApJ, 600, L75. ADS Abstract and Links

  51. 4. Oscillation frequencies and mode lifetimes in α Centauri A (2004)
    Bedding, T.R. et al.  2004, ApJ, 614, 380. ADS Abstract and Links

  52. 5. Solar-like Oscillations in α Centauri B
    Kjeldsen et al. 2005, ApJ, 635, 1281. ADS Abstract and Links

  53. 6. Solar-like Oscillations in the Metal-poor Subgiant ν Indi: Constraining the Mass and Age Using Asteroseismology
    Bedding et al. 2006, ApJ, 647, 558. ADS Abstract and Links

  54. 7. Solar-like oscillations in the G2 subgiant β Hydri from dual-site observations
    Bedding et al. 2007, ApJ, 663, 1315. ADS Abstract and Links

  55. 8. Solar-like oscillations in the metal-poor subgiant ν Indi: II. Acoustic spectrum and mode lifetime
    Carrier et al. 2007, A&A, 470, 1059. ADS Abstract and Links

  56. 9.The amplitude of solar oscillations using stellar techniques
    Kjeldsen H. et al. 2008, ApJ, 682, 1370. ADS Abstract and links





AAPS Planets : New Planets and Past Announcements



1 May 2011 - AAPS Discovers Two New Planets
               .... and asks "What do we really know about habitable exomoons?"


  1. Two papers have recently been published presenting new planets from the Anglo-Australian Planet Search. The first (HD102365b) is a Neptune mass planet in a 122d orbit - and this planet (unlike many of the other Neptune-mass and smaller planets recently discovered) orbits its star in splendid and lonely isolation.

    The second planet (HD38283b) has an orbital period of almost exactly one year - prompting us to ask just what we do know about the formation and habitability of the possible moons of such a planet.


   


31 January 2011 - AAPS Simulations measure prevalence of Jupiter Analogs

  1. The detailed simulation of over a decade's worth of AAPS observations have revealed that only ~3% of our target stars have been revealed to host "Jupiter analogs" (ie. gas-giant planets in long-period orbits). And that at most ~30% could possibly be hiding such planets

   


14 Dec 2009 - Detection of a Neptune mass planet around the G dwarf 61 Vir


  1. The Anglo-Australian Planet Search and the Keck planet search have today jointly announced the detection of 4 new exoplanets orbiting 2 stars.


  2. The "solar twin" 61 Vir has been found to host 3 planets ranging in mass from 5 to 22 times the mass of the Earth, while the G-type star 23 Lib has been found to host a second planet (in addition to its previously detected 280d planet) in a 14 year Jupiter-like orbit.


  3. The 5.3 Mearth companion to 61 Vir is particularly exciting - it is the first "Super Earth" planet to be found orbiting a Sun-like star (rather than a K or M-dwarf).


  4. For more details see the Anglo-Australian Observatory and UNSW press pages, and the AAPS Planets page.


  5. The two papers presenting these results are


  6. A Super-Earth and two Neptunes Orbiting the Nearby Sun-like star 61 Virginis
    Vogt et al. 2010, The Astrophysical Journal, ApJ, 708, 1366. Abstract and Links

  7. A long-period planet orbiting a nearby Sun-like star
    Jones et al. 2010, Monthly Notices of the Royal Astronomical Society, 403, 1703. Abstract and Links




  1. 23 Feb 2009 - Detection of a Neptune mass planet around the G dwarf HD16417


  2. The Anglo-Australian Telescope has detected a planet with a mass at least 22.1 times the mass of the Earth in orbit with a 17.4 day period around the G1 dwarf HD16417. This detection arose from 48n of continuous observing on the AAT, specifically targeted at detecting low-mass planets. Such observing runs beat down the window function at short periods, significantly improving the detectability of terrestrial-mass planets. A forthcoming paper will analyse the data using detailed Monte-Carlo simulations to quantify the detection limits for terrestrial-mass planets obtained with this new observing strategy.


  3. Abstract and Links for the in-press paper.



    1 Sep 2008 - Detection of a planet orbiting the M dwarf GJ832


  1. The Anglo-Australian Telescope has detected a planet with a mass of at least 0.64 Mjup in a 9.4+-0.4 year period orbiting the M1.5 dwarf GJ832


  2. Abstract and Links to the published paper.



  3. 7 Feb 2007 - AAPS announces three new planets orbiting G-type dwarfs

  4. NASA ADS Abstract and Links for published paper


  5. August 2006 - AAPS publishes an exoplanetary system in a 2:1 resonance.

  6. ApJ paper on the HD73526 resonant system.


  7. June 2006 - AAPS publishes two new high eccentricity planets.

  8. MNRAS paper on HD187085 and HD20782 systems


  9. 15 Sep 2004 - AAPS announces five new extra-solar planets!

  10. The five new planets include the first multiple planet systems detected by the AAPS, and three low-mass (ie Saturnian- or sub-Saturnian-mass planets).

  11. The multiple planet systems include two planets detected around the star mu Ara (in the constellation of Ara "The Altar"). The inner planet has an orbital period of 645 days and a minimum mass of 1.7 Jupiter masses. The outer planet has an orbital period of 8.2 years and a minimum mass of  3.1 Jupiter masses. Both planets have quite eccentric (ie non-circular) orbits. These two planets were recently "joined" by a third inner (but very much smaller) planet in a 9 day orbit announced by Santos et al.

  12. The three low-mass planets have all been detected with orbital periods of between 26 and 129 days, and minimum masses of between 0.16 and 0.4 times that of Jupiter. These low-mass planets are exciting to the Anglo-Australian Planet Search team because they all have small velocity amplitudes - that is the represent the detection of quite small "wobbles" in the parent stars due to these planets. Indeed at just 12 to 18m/s these results obtained from data streams stretching back to 1998, represent exactly the levels of precision that our search needs to attain to detect Solar Systems like our own around other stars via the orbital motion of a Jupiter-like planet in a Jupiter-like 12 year orbit. They give us confidence that in the next 6 years, if there are any "Solar System-like" systems amongst our 240 targets stars, we will find them.

  13. The published papers are available with data on HD160691 & HD158457 and HD117618, HD102117 & HD208487


  14. 4 July 2003 : detection of the best Solar System analog yet found orbiting HD70642

  15. “A Planet in a Circular Orbit with a 6 year Period” (2003)
    ApJ, 593, L43. ADS Abstract and Links


  16. AAO Press Release (with Animation & Stills), PPARC  Press Release, Animation by J.Rowe of HD70642
    System



  17. Upper right - Artists impression of the HD70642 gas giant planet, with hypothetical moons.
    Photo Credit: David A. Hardy, astroart.org (c) PPARC.

  18. Lower left - HD70642 Orbital graphic








  19. 17 Sep 2002 : detection of a Jupiter-mass planet orbiting tau1 Gruis

  20. “An exoplanet in orbit around tau1 Gruis” (2003), MNRAS, 341, 948.
    ADS Abstract and Links



Photo Credit: David A. Hardy, astroart.org

(c) PPARC




  1. 8 July 2002 : detection of a sub-Saturn "hot Jupiter"
      planet orbiting HD76700

  2. 26 June 2002: detection of an eccentric gas giant planet orbiting HD2039

  3. 13 June 2002: AAPS, Lick and Keck detect 15 New Planets, including Lick discovery of 55 Cnc c : the first Jupiter-like planet in a Jupiter-like orbit!  (AAO press release, NASA graphics, UK press release)

  4. Photo Credit: Lynette Cook



  5. 16 October 2001 : the detection of three
    new extra-solar planets 
    (
    AAO press release )
    Photo Credit: David Hardy, astroart.org (c) PPARC




  6. 11 December 2000 :  the detection of three extra-solar planets and a brown dwarf (AAO press release, UK press release)
     


Page maintained by Chris Tinney.

 

The Anglo-Australian Planet Search (AAPS) is a long-term program being carried out on the 3.9m Anglo-Australian Telescope (AAT) to search for giant planets around more than 240 nearby Solar-type stars with V<8. We use the "Doppler wobble" technique to search for these otherwise invisible extra-solar planets, and achieve the highest long-term precision demonstrated by any Southern Hemisphere planet search.