Request for optical photometry of the bright X-ray binary V884 Sco (4U 1700-377)
Active Dates: June 30, 2009 – Aug. 10, 2009
Abstract:
Dr. Jerome Orosz has requested the assistance of southern bright star observers in observing the high-mass X-ray binary star V884 Sco. Orosz and collaborators are attempting to measure the mass of the compact object to clarify whether the object is a black hole or a neutron star. Optical photometry of the ellipsoidal variations of V884 Sco will be used in conjunction with optical spectroscopy to be performed at Las Campanas in mid-July and early August 2009 to measure the dynamical properties of the system. Orosz requests time-series B and V observations of this bright system beginning now (2009 June 30) and continuing through early August 2009.
Justification:
If it has a neutron star, it has by far the most massive neutron star known. Furthermore, the high mass would rule out all sorts of equations of state for neutron star matter. On the other hand, if the compact object is a black hole, it would be by far the least massive black hole known, and its mass would raise all sorts of interesting questions about the formation of black holes, and what kinds of stars produce black holes.
Requested Data Types:
Photometry, Spectroscopy
Targets
| Name | Magnitude | Variability Type | Photometry Notes | Spectroscopy Notes |
|---|---|---|---|---|
| BMAM-V884 | 11.90 | EA |
Cadence: Not Specified Precision: 100 |
Cadence: Not Specified Resolution: 250 Desired SNR: 100 |
Spectroscopy Lines:
No spectroscopy lines provided
Photometry Filters:
No photometry filters provided
Comparison Stars:
No comparison stars provided
Co-Authorship
Observers are not eligible for co-authorship.
Additional Observer Input:
Not provided
Additional Submission Location:
Not provided
Forum URL
N/A
Notes:
Principal Investigator: Dr. Jerome Orosz (SDSU); Imported Campaign (Alert Notice #397)