XG EXPERIMENT

The detector essentially consisted of an array of 16 independent square NaI(Tl) scintillator crystals, fourteen of which were 10 mm thick and the other two 3 mm.

During this flight four galactic X-ray sources were observed, namely the transient recurrent X-ray pulsar A0535+26, the Crab Nebula, Cygnus X-1 and X Persei.

Balloon launched on: 10/4/1980 at 23:02 utc
Launch site: Columbia Scientific Balloon Facility, Palestine, Texas, US  
Balloon launched by: National Scientific Balloon Facility (NSBF)
Balloon manufacturer/size/composition: Zero Pressure Balloon Winzen 727.460 m3 (15.24 Microns - Stratofilm) - SF 404.85-060-NSCR-01
Balloon serial number: W26.59-2-01
Flight identification number: 1220P
End of flight (L for landing time, W for last contact, otherwise termination time): 10/5/1980 at 13:18 utc
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): F 15 h
Landing site: 17 Miles N of Meridian, Mississippi, US
Payload weight: 1387 kgs

• Balloon program for hard-X-ray astronomy IL Nuovo Cimento C Novembre-Dicembre 1984, Volume 7, Issue 6, pp 648-655
• Hard X-ray emission from the recurrent transient A0535 + 26 during its 1980 high-intensity outburst Advances in Space Research vol. 3, no. 10-12, 1984, p. 47
• Hard X-ray observation of galactic X-ray sources Advances in Space Research - Volume 5, Issue 3, 1985, Pages 125-128
• Hard X-ray observation of the transient X-ray pulsar A0535+26 Max-Planck Inst. Phys. and Astrophys. Accreting Neutron Stars p 112-116
• National Scientific Balloon Facility Annual Report FY 1981 National Center for Atmospheric Research, April 1982
• The Pulsed Spectrum of the Transient Source A0535+26 in the Hard X-Ray Range Physica Scripta. Vol. T7, 11 1-1 12, 1984
• The X-ray pulsar A0535 + 26 - Pulse profile and its time variability in hard X-rays Astrophysical Journal, Part 1 vol. 298, Nov. 15, 1985, p. 585
• The X-ray pulsar A0535+26 in hard X-rays - Average spectrum, pulse-phase spectroscopy, and spectral time variability Astrophysical Journal, Part 1 vol. 331, Aug. 1, 1988, p. 313