Notes for PSR B1620-26

update: 1 October 2004

The planet:

• Detection method: Timing
• Basic data:

  M.sini ( MJ):	2.5 ± 1
  Semi-major axis (AU):	23
  Orbital period (yrs):	~ 100
  Eccentricity:	-
  Inclination (deg):	55+14-8

• Remarks:
  10 Jul. 2003: Planet parameters determined with Hubble by measurements of the white dwarf companion characteristics (Sigurdsson et al, 2003)
  Compare with old parameters
  1999: The pulsar is in a binary system (period = 191.4428 d.) with a white dwarf companion (Thorsett et al. 1999); this explains the uncertainties in the fitting of the planet parameters.
• References:
  1. ARZOUMIAN Z., JOSHI K., RASIO F. & THORSETT S., 1996
     Orbital Parameters of the PSR B1620-26 Triple System.
     in Pulsars: Problems and Progress,
     eds. M. Bailes, S. Johnston, & M. Walker
     (IAU Colloquium 160, Astronomical Soc. of the Pacific, Conf. Series), p.525.
     paper
  2. BACKER D. C., FOSTER R. S. & SALLMEN S., 1993
     A second companion of the millisecond pulsar 1620-26
     Nature, 365, 817
  3. BEER M., KING A., & PRINGLE J., 2004
     The planet in M4: implications for planet formation in globular clusters.
     MNRAS, accepted
     preprint
  4. FORD E., JOSHI K., RASIO F. & ZBARSKI B., 1999
     Theoretical Implications of the PSR B1620-26 Triple System and its Planet
     ApJ., 528, 336
     paper preprint
  5. JOSHI K. & RASIO F., 1997
     Distant Companions and Planets around Millisecond Pulsars
     ApJ., 479, 948
     paper
     (ApJ., 488, 901: erratum)
  6. RASIO F., 1998
     New Evidence for a Planet or Brown Dwarf in Orbit Around PSR B1620-26.
     in Proc. of Texas Symposium on Relativistic Astrophysics, eds. A. Olinto et al. (Ann. N.Y. Acad. Sci.), in press.
  7. RASIO F. A., 1994
     Is there a planet in the PSR 1620-26 triple system?
     ApJ. Letters, 427, 107L
     abstract and paper.
  8. RICHER H., IBATA R., FAHLMAN G. & HUBER M., 2003
     The Pulsar-White Dwarf-Planet System in Messier 4: Improved Astrometry.
     ApJ, accepted
     preprint
  9. SCHEARER A., BUTLER R., REDFERN R., CULLUM M.; & DANKS A., 1996
     A Search for the Optical Counterpart of the Triple Pulsar System PSR B1620-26 in M4.
     ApJ.L., 473, L115
     paper
  10. SIGURDSSON S., RICHER H., HANSEN B., STAIRS I & THORSETT S., 2003
      A Young White Dwarf Companion to Pulsar B1620-26: Evidence for Early Planet Formation.
      Science, 301 193
      paper paper
  11. SIGURDSSON S., 1995
      Assessing the Environmental Impact on PSR~B1620-26 in M4.
      ApJ., 452, 323 abstract
  12. THORSETT S., ARZOUMANIAN Z., CAMILO F. & LYNE A., 1999
      The Triple Pulsar System PSR B1620-26 in M4
      ApJ. 523, 763
      paper

The star (binary pulsar-WD):

• Distance: 3.8 kpc
  This distance is deduced from a DM of 63 pc.cm^-3, using the on-line model of Taylor and Cordes (ApJ., 411, 674, 1993).
• Stellar type: WD, PSR
• Apparent magnitude: V_WD = 24
• Coordinates (2000): RA = 16 23 38, DEC = -26 -21 -53
• Metallicity: [Fe/H] = -
• Mass (M_sun): M_WD = 0.34 ± 0.04, M_PSR = 1.35
• Age: A_WD = 0.5 Gy
• Binary orbit:
  • Period: 191.4428 d.
  • Eccentricity: 0.025
  • Inclination (deg): 55⁺¹⁴_-8
• More data:
  Basic Data (from simbad )
  • Basic Data (from the Princeton Pulsar Group; enter `1620-26' in the `pulsar catalog information' field).
  • Most recent refs. (from ADS; enter `PSR 1620-26' in the `objects' field)