Notes for 97-BLG-41

update: 5 April 2002

The planet:

• Detection method: Microlensing
• Basic data:
  • M:       ~ 3 M_J
  • Semi-major axis:      ~ 7 AU
  • Orbital period:      unknown
  • Eccentricity:       unknown
• Remarks: 1/ The star is a binary with a separation of ~ 1.8 AU and masses of ~1 and ~3.8 solar masses respectively. The planet is in orbit around the binary.
  2/ The 7 AU value for the distance to the binary star is valid at the single instant of observation. The eccentricity may be high (especially since the central star is a binary) and the orbital period very uncertain (> about 10 years from Kepler law)
  3/ The PLANET Team explains the same data and its own observations by a "rotating binary lens of mass ratio q=0.34 and angular separation d ~ 0.5 (in units of the Einstein ring radius)" (Albrow et al. 1999)
• References:
  1. ALBROW M., BEAULIEU J.-Ph., CALDWELL J., DOMINIK M., GAUDI B.S., GOULD A., GREENHILL J., HILL K., KANE S., MARTIN R., MENZIES J., NABER R., POLLARD K., SACKETT P., SAHU K., VERMAAK P., WATSON R., WILLIAMS A., (The PLANET Collaboration), BOND H. & van BEMMEL I., 1999
     Detection of Rotation in a Binary Microlens: PLANET Photometry of MACHO 97-BLG-41
     ApJ., 534, 894
     paper
  2. BENNET D., RHIE S., BECKER A., BUTLER N., DANN J., KASPI S., LEIBOWITZ E., LIPKIN Y., MAOZ D., MENDELSON H., PETERSON B., QUINN J., SHEMMER O., THOMSON S. & TURNER S., 1999a
     Gravitational Microlensing Evidence for a Planet Orbiting a Binary Star System
     Nature, submitted
     preprint
  3. BENNET D., RHIE S., BECKER A., BUTLER N., DANN J., KASPI S., LEIBOWITZ E., LIPKIN Y., MAOZ D., MENDELSON H., PETERSON B., QUINN J., SHEMMER O., THOMSON S. & TURNER S., 1999b
     Discovery of a planet orbiting a binary star system from gravitational microlensing.
     Nature, 402, 57
     paper
  4. MORIWAKI K. & NAKAGAWA Y.? 2002
     Stability of a planet in the binary system Macho-97-BLG-41.
     Astron. J., 124, 3364
     paper
• Other Web pages:
  1. Microlensing Planet Search Project
  2. Rotating binary star model by the PLANET Team

The star:

• Distance:
• Spectral type:
• Apparent magnitude:
• Absolute luminosity:
• Coordinates (2000):          
• More data:
  • Basic Data (from simbad )
  • Most recent refs. (from ADS; enter ` ' in the `objects' field)