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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"

21106 results found.

  1. LIGO/Virgo S190828l: No significant candidates in TAROT-GRANDMA observations
  2. GRB 190829A: Liverpool Telescope observations
  3. Fermi trigger No 588962322 Global MASTER-Net observations report
  4. GRB 190829A: NOEMA detection of the mm afterglow
  5. Fermi trigger No 588931056 Global MASTER-Net observations report
  6. GRB 190829A: Liverpool Telescope optical photometry
  7. GRB 190829A: UKIRT detection of the NIR Afterglow
  8. GRB 190829A: MMT detection of the optical afterglow
  9. GRB 190829A: Follow up VLA and VLBI radio observations urged
  10. GRB 190829A: KAIT Detection of the Optical Afterglow
  11. GRB 190829A: Fermi-LAT Upper Limits
  12. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  13. Fermi trigger No 588838851 Global MASTER-Net observations report
  14. GRB 190829A: Swift/UVOT detection of an optical afterglow with a rise
  15. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  16. GRB190829A: Detection of VHE gamma-ray emission with H.E.S.S.
  17. GRB 190829A: 10.4m GTC spectroscopy
  18. LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations
  19. LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
  20. GRB 190829A:: MASTER-net bright and decay OT detection
  21. LIGO/Virgo S190829u Global MASTER-Net observations report
  22. GRB 190829A: Dabancheng-0.5m optical afterglow detection
  23. Fermi trigger No 588801358 Global MASTER-Net observations report
  24. GRB 190828B: optical upper limit from 0.5m Savelli Robotic Telescope
  25. LIGO/Virgo S190828l: Upper limits from Insight-HXMT/HE observations
  26. GRB 190828B: Swift/UVOT Upper Limits
  27. GRB 190828A: Swift-XRT observations
  28. GRB 190823A: AstroSat CZTI detection
  29. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx
  30. LIGO/Virgo S190828l: No counterpart candidates in Fermi-LAT observations
  31. LIGO/Virgo S190828l: No transient candidates in CALET observations
  32. LIGO/Virgo S190828j: No transient candidates in CALET observations
  33. LIGO/Virgo S190828l: no counterpart candidates in the Swift/BAT Observations
  34. LIGO/Virgo S190828j: no counterpart candidates in the Swift/BAT Observations
  35. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  36. LIGO/Virgo S190828j: No counterpart candidates in Fermi-LAT observations
  37. GRB 190828A: Tiled Swift observations
  38. Integral GRB190828.78 Global MASTER-Net observations report
  39. LIGO/Virgo S190814bv: no variation of DESGW candidates AT 2019onj and AT 2019okr from ENGRAVE VLT/HAWK-I observations, and archival detection
  40. LIGO/Virgo S190814bv: Swift UVOT - no new counterpart candidates identified
  41. LIGO/Virgo S190828l: Upper limits from Fermi-GBM Observations
  42. LIGO/Virgo S190828j: Upper limits from Fermi-GBM Observations
  43. Swift GRB190828.54 Global MASTER-Net observations report
  44. LIGO/Virgo S190828l: Upper limits from AGILE-GRID observations
  45. LIGO/Virgo S190828l Global MASTER-Net observations report
  46. LIGO/Virgo S190828l: Coverage and upper limits from MAXI/GSC observations
  47. LIGO/Virgo S190828l: No counterpart candidates in AGILE-MCAL observations
  48. LIGO/Virgo S190828j: Coverage and upper limits from MAXI/GSC observations
  49. LIGO/Virgo S190828j: Upper limits from AGILE-GRID observations
  50. LIGO/Virgo S190828l: No counterpart candidates in HAWC observations
  51. LIGO/Virgo S190828j: No counterpart candidates in HAWC observations
  52. LIGO/Virgo S190828j: No counterpart candidates in AGILE-MCAL observations
  53. LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433
  54. Fermi trigger No 588597173 Global MASTER-Net observations report
  55. LIGO/Virgo S190814bv: Optical non-detection of radio source AT2019osy from CFHT
  56. Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
  57. LIGO/Virgo S190814bv: DECam-GROWTH detection of an optical counterpart to the radio source AT2019osy
  58. LIGO/Virgo S190814bv: Detection of a candidate radio counterpart with ASKAP
  59. LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign
  60. LIGO/Virgo S190814bv: CFHTphotometryof AT2019npv
  61. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num
  62. LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova
  63. GRB 190824A: Swift/UVOT Upper Limits
  64. LIGO/Virgo S190814bv: LCO Photometry of DG19wxnjc/AT2019npv
  65. GRB 190823A: Swift-XRT observations
  66. Fermi trigger No 588398821 Global MASTER-Net observations report
  67. LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field
  68. GRB 190816A: Swift-XRT afterglow detection
  69. LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations
  70. Fermi trigger No 588350802 Global MASTER-Net observations report
  71. GRB 190823A: Tiled Swift observations
  72. LIGO/Virgo S190814bv: DESGW photometry of AT2019npv
  73. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  74. LIGO/Virgo S190814bv: Further Pan-STARRS z-band observations and AT2019npv photometry
  75. Fermi trigger No 588185734 Global MASTER-Net observations report
  76. Fermi GBM-190816: Coverage and upper limits from MAXI/GSC observations
  77. Fermi trigger No 588115134 Global MASTER-Net observations report
  78. GRB 190821A: Swift/UVOT Upper Limits
  79. GRB 190821A: MASTER VWFC syncronous optical observations
  80. LIGO/Virgo S190814bv: ENGRAVE VLT/HAWK-I observations and archival detection of the CFHT candidate
  81. Fermi GBM-190816: MASTER-Net optical observation report
  82. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  83. LIGO/Virgo S190814bv: a potential faint optical counterpart in CFHT imaging
  84. LIGO/Virgo S190822c: CLU/NED Galaxies in the 50% Localization Volume
  85. LIGO/Virgo S190822c Global MASTER-Net observations report
  86. LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
  87. Fermi GBM-190816: Upper Limits from Swift/BAT Observations
  88. GRB 190821A: T60 Les Makes optical detection of the afterglow
  89. Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
  90. Swift GRB190821.72 Global MASTER-Net observations report
  91. Fermi trigger No 588100239 Global MASTER-Net observations report
  92. Fermi GBM-190816: No counterpart candidates in Fermi-LAT observations
  93. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019noq and AT2019ntn
  94. Fermi-LAT Gamma-ray Observations of IceCube-190819A
  95. Fermi GBM-190816: One candidate counterpart from the Zwicky Transient Facility
  96. LIGO/Virgo S190814bv: Further Pan-STARRS observations and transient sources
  97. LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
  98. LIGO/Virgo GBM-190816: no counterpart candidates in the Swift/BAT Observations
  99. Fermi GBM-190816: No counterpart candidates in HAWC observations
  100. IceCube-190819A: Upper limits from Fermi-GBM Observations

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