DGT (Directional Gamma-Ray Telescope)

A first-generation (balloon-borne) coded-aperture imaging telescope covering the energy range 160 keV - 10 MeV using an array of BGO scintillators as a detection plane.

It was capable of imaging photons in the 160 keV to 10 MeV energy range.

This was the first successful flight after two consecutives failures due to balloon burst (1982 and 1983).

During the flight were observed the Crab Nebula, the Cygnus region, NGC 4151, SS433, 3C273, and CG135+1.

Balloon launched on: 10/1/1984 at 14:25 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 SF-384.52-060-NSCR-01
Balloon serial number: W21.62-2-01
Flight identification number: 1379P
End of flight (L for landing time, W for last contact, otherwise termination time): 10/2/1984 at 22:35 utc
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): 32 h
Landing site: 4 miles N of Mabank, Texas, US
Overall weight: 1600 kgs

The telescope was succesfull launched at 14:25 utc on October 1, 1984 reaching an height of near 40 km at approximately 17:00 utc.

The payload remained at float altitude until the flight was terminated 32 hours later on October 2 at 22:35 utc.

• A Balloon-Borne Coded Aperture Telescope for Low-Energy Gamma- Ray Astronomy Nuclear Instruments and Methods in Physics Research A274 (1989) 362
• A review of Imaging Observations Obtained with the University of New Hampshire Gamma-Ray Telescope (dgt) 20th International Cosmic Ray Conference Moscow, Volume 1, p.66
• A Search for Gamma-Ray Lines from the Crab, Cygnus X-1 and NGC 4151 20th International Cosmic Ray Conference Moscow, Volume 1, p.172
• Gamma-ray imaging observations of the Crab and Cygnus regions Ph.D Thesis by Mark Lewis McConnell, University of New Hampshire, 1987
• Gamma-ray observations of Cygnus X-1 and Cygnus X-3 using a coded-aperture telescope Astrophysical Journal, Part 1, vol. 343, Aug. 1, 1989, p. 317
• Gamma-ray observations of the Crab Region using a coded-aperture telescope Astrophysical Journal, Part 1, vol. 321, Oct. 1, 1987, p. 543-552
• High-Energy Emission from Cygnus X-1 20th International Cosmic Ray Conference Moscow, Volume 1, p.58
• Observations of cosmic gamma ray sources and their contribution to the diffuse gamma ray background Ph.D Thesis by Debadarshi Bhattacharya, University of New Hampshire, 1990
• The Directional Gamma-Ray Telescope (DGT) Alan Owens website (now available via Archive.Org)