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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21097 results found.

  1. GRB 190829A: KAIT Detection of the Optical Afterglow
  2. GRB 190829A: Fermi-LAT Upper Limits
  3. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  4. Fermi trigger No 588838851 Global MASTER-Net observations report
  5. GRB 190829A: Swift/UVOT detection of an optical afterglow with a rise
  6. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  7. GRB190829A: Detection of VHE gamma-ray emission with H.E.S.S.
  8. GRB 190829A: 10.4m GTC spectroscopy
  9. LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations
  10. LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
  11. GRB 190829A:: MASTER-net bright and decay OT detection
  12. LIGO/Virgo S190829u Global MASTER-Net observations report
  13. GRB 190829A: Dabancheng-0.5m optical afterglow detection
  14. Fermi trigger No 588801358 Global MASTER-Net observations report
  15. GRB 190828B: optical upper limit from 0.5m Savelli Robotic Telescope
  16. LIGO/Virgo S190828l: Upper limits from Insight-HXMT/HE observations
  17. GRB 190828B: Swift/UVOT Upper Limits
  18. GRB 190828A: Swift-XRT observations
  19. GRB 190823A: AstroSat CZTI detection
  20. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx
  21. LIGO/Virgo S190828l: No counterpart candidates in Fermi-LAT observations
  22. LIGO/Virgo S190828l: No transient candidates in CALET observations
  23. LIGO/Virgo S190828j: No transient candidates in CALET observations
  24. LIGO/Virgo S190828l: no counterpart candidates in the Swift/BAT Observations
  25. LIGO/Virgo S190828j: no counterpart candidates in the Swift/BAT Observations
  26. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  27. LIGO/Virgo S190828j: No counterpart candidates in Fermi-LAT observations
  28. GRB 190828A: Tiled Swift observations
  29. Integral GRB190828.78 Global MASTER-Net observations report
  30. LIGO/Virgo S190814bv: no variation of DESGW candidates AT 2019onj and AT 2019okr from ENGRAVE VLT/HAWK-I observations, and archival detection
  31. LIGO/Virgo S190814bv: Swift UVOT - no new counterpart candidates identified
  32. LIGO/Virgo S190828l: Upper limits from Fermi-GBM Observations
  33. LIGO/Virgo S190828j: Upper limits from Fermi-GBM Observations
  34. Swift GRB190828.54 Global MASTER-Net observations report
  35. LIGO/Virgo S190828l: Upper limits from AGILE-GRID observations
  36. LIGO/Virgo S190828l Global MASTER-Net observations report
  37. LIGO/Virgo S190828l: Coverage and upper limits from MAXI/GSC observations
  38. LIGO/Virgo S190828l: No counterpart candidates in AGILE-MCAL observations
  39. LIGO/Virgo S190828j: Coverage and upper limits from MAXI/GSC observations
  40. LIGO/Virgo S190828j: Upper limits from AGILE-GRID observations
  41. LIGO/Virgo S190828l: No counterpart candidates in HAWC observations
  42. LIGO/Virgo S190828j: No counterpart candidates in HAWC observations
  43. LIGO/Virgo S190828j: No counterpart candidates in AGILE-MCAL observations
  44. LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433
  45. Fermi trigger No 588597173 Global MASTER-Net observations report
  46. LIGO/Virgo S190814bv: Optical non-detection of radio source AT2019osy from CFHT
  47. Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
  48. LIGO/Virgo S190814bv: DECam-GROWTH detection of an optical counterpart to the radio source AT2019osy
  49. LIGO/Virgo S190814bv: Detection of a candidate radio counterpart with ASKAP
  50. LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign
  51. LIGO/Virgo S190814bv: CFHTphotometryof AT2019npv
  52. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num
  53. LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova
  54. GRB 190824A: Swift/UVOT Upper Limits
  55. LIGO/Virgo S190814bv: LCO Photometry of DG19wxnjc/AT2019npv
  56. GRB 190823A: Swift-XRT observations
  57. Fermi trigger No 588398821 Global MASTER-Net observations report
  58. LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field
  59. GRB 190816A: Swift-XRT afterglow detection
  60. LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations
  61. Fermi trigger No 588350802 Global MASTER-Net observations report
  62. GRB 190823A: Tiled Swift observations
  63. LIGO/Virgo S190814bv: DESGW photometry of AT2019npv
  64. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  65. LIGO/Virgo S190814bv: Further Pan-STARRS z-band observations and AT2019npv photometry
  66. Fermi trigger No 588185734 Global MASTER-Net observations report
  67. Fermi GBM-190816: Coverage and upper limits from MAXI/GSC observations
  68. Fermi trigger No 588115134 Global MASTER-Net observations report
  69. GRB 190821A: Swift/UVOT Upper Limits
  70. GRB 190821A: MASTER VWFC syncronous optical observations
  71. LIGO/Virgo S190814bv: ENGRAVE VLT/HAWK-I observations and archival detection of the CFHT candidate
  72. Fermi GBM-190816: MASTER-Net optical observation report
  73. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  74. LIGO/Virgo S190814bv: a potential faint optical counterpart in CFHT imaging
  75. LIGO/Virgo S190822c: CLU/NED Galaxies in the 50% Localization Volume
  76. LIGO/Virgo S190822c Global MASTER-Net observations report
  77. LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
  78. Fermi GBM-190816: Upper Limits from Swift/BAT Observations
  79. GRB 190821A: T60 Les Makes optical detection of the afterglow
  80. Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
  81. Swift GRB190821.72 Global MASTER-Net observations report
  82. Fermi trigger No 588100239 Global MASTER-Net observations report
  83. Fermi GBM-190816: No counterpart candidates in Fermi-LAT observations
  84. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019noq and AT2019ntn
  85. Fermi-LAT Gamma-ray Observations of IceCube-190819A
  86. Fermi GBM-190816: One candidate counterpart from the Zwicky Transient Facility
  87. LIGO/Virgo S190814bv: Further Pan-STARRS observations and transient sources
  88. LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
  89. LIGO/Virgo GBM-190816: no counterpart candidates in the Swift/BAT Observations
  90. Fermi GBM-190816: No counterpart candidates in HAWC observations
  91. IceCube-190819A: Upper limits from Fermi-GBM Observations
  92. LIGO/Virgo S190814bv: GRAWITA TNG NIR imaging of AT2019nqq and AT2019nqc
  93. LIGO/Virgo S190814bv: No strong counterpart candidates in Swift/XRT observations
  94. GRB 190816A: Swift-XRT observations
  95. LIGO/Virgo S190814bv: No candidates from image subtraction in DCT galaxy targeted search
  96. LIGO/Virgo S190814bv: WIRC NIR imaging follow-up of DECam transients
  97. LIGO/Virgo S190814bv: Additional candidates identified in DECam images by the DECam-GROWTH team
  98. LIGO/Virgo S190814bv: Prioritization of Counterpart Candidates based on a Photometric Redshift Analysis by the DECam-GROWTH Team
  99. LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
  100. Fermi trigger No 587775150 Global MASTER-Net observations report

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