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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"

22215 results found.

  1. Fermi trigger No 649390368: Global MASTER-Net observations report
  2. GRB 210730A: TNG optical observations
  3. GRB 210726A: Chandra detection of the X-ray afterglow
  4. Fermi trigger No 649313854: Global MASTER-Net observations report
  5. GRB 210730A: Swift/UVOT Upper Limits
  6. GRB 210730A: Swift detection of a burst near M82
  7. GRB 210726A: OSIRIS/GTC observations
  8. GRB 210726A: 6 GHz VLA radio upper limit
  9. GRB 210702A: MeerKAT radio detection
  10. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  11. Fermi trigger No 649072251: Global MASTER-Net observations report
  12. GRB 210725A: AbAO optical upper limit
  13. GRB 210724A: Swift/UVOT Upper Limits
  14. GRB 210723A: Swift/UVOT Upper Limits
  15. GRB 210725A: Swift/UVOT Upper Limits
  16. GRB 210725B: Swift/UVOT Upper Limits
  17. Swift GRB210726.80: Global MASTER-Net observations report
  18. Fermi trigger No 648959581: Global MASTER-Net observations report
  19. Swift GRB 210725B: Global MASTER-Net observations report
  20. GRB 210724A: Afterglow candidate from OSIRIS/GTC
  21. GRB 210722A: continued Assy optical observations
  22. GRB 210722A: Nanshan/NEXT further optical observations
  23. Fermi trigger No 648868114: Global MASTER-Net observations report
  24. Swift GRB210725.16: Global MASTER-Net observations report
  25. GRB210724A: MeerLICHT upper limits
  26. Swift GRB210724.84: Global MASTER-Net observations report
  27. GRB 210722A: continued Assy optical observations
  28. GRB 210722A: D50 optical detection
  29. Swift GRB 210723A: Global MASTER-Net observations report
  30. GRB 210722A: Kitab optical observations, light curve
  31. GRB 210722A: Redshift from OSIRIS/GTC
  32. GRB 210722A: RATIR Optical Observations
  33. GRB 210722A: Swift/UVOT Detection
  34. GRB 210722A: GIT optical detection and preliminary analysis
  35. Swift GRB 210722A: Global MASTER-Net observations report
  36. GRB 210702A: ALMA detection of mm-band rebrightening
  37. GRB 210702A: ATCA detection of radio rebrightening
  38. GRB 210722A: Nanshan/NEXT optical afterglow observations
  39. Fermi trigger No 648602917: Global MASTER-Net observations report
  40. Fermi-LAT Gamma-ray Observations of IceCube-210717A
  41. Fermi trigger No 648359752: Global MASTER-Net observations report
  42. Fermi trigger No 648278666: Global MASTER-Net observations report
  43. Konus-Wind detection of GRB 210714A
  44. Fermi trigger No 647942198: MASTER optical afterglow detection
  45. GRB 210704A: Zeiss-1000/SAO-RAS optical observations
  46. Fermi trigger No 648033323: Global MASTER-Net observations report
  47. Fermi trigger No 648024201: Global MASTER-Net observations report
  48. Fermi trigger No 647942198: Global MASTER-Net observations report
  49. GRB 210712A: Swift/UVOT Upper Limits
  50. GRB 210712A: BOOTES-3/YA optical upper limit
  51. Fermi trigger No 647805873: Global MASTER-Net observations report
  52. GRB 210704A: Lowell Discovery Telescope Optical Observations
  53. Fermi trigger No 647775795: Global MASTER-Net observations report
  54. GRB 210704A: Continued Gemini-North NIR K-band Detections
  55. GRB 210704A: INTEGRAL observations
  56. GRB 210704A: NOT optical observations and color change
  57. GRB210704A: Gemini near-infrared upper limits
  58. Fermi trigger No 647653174: Global MASTER-Net observations report
  59. GRB 210704A: Assy optical afterglow upper limit
  60. Fermi trigger No 647641569: Global MASTER-Net observations report
  61. Fermi trigger No 647624281: Global MASTER-Net observations report
  62. GRB 210704A: OSIRIS/GTC Observations and Archival Detection of the Possible Host Galaxy
  63. MAXI GRB210709.93: Global MASTER-Net observations report
  64. Fermi trigger No 647522278: Global MASTER-Net observations report
  65. GRB 210704A: Gemini-North Infrared Source Detection
  66. GRB 210704A: further TNG optical observations
  67. GRB 210706A: Swift/XRT afterglow confirmation
  68. GRB 210708B: Swift-BAT refined analysis
  69. Fermi GRB 210709A: Global MASTER-Net observations report
  70. Swift GRB 210708B: Global MASTER-Net observations report
  71. GRB 210708A: Swift/UVOT Upper Limits
  72. GRB 210702A: ATCA detection
  73. GRB 210702A: ALMA detection
  74. IceCube-210629A - Spectroscopic observation of AT2021osi
  75. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 7
  76. Swift GRB210708.10: Global MASTER-Net observations report
  77. Fermi trigger No 647365516: Global MASTER-Net observations report
  78. Fermi trigger No 647271699: Global MASTER-Net observations report
  79. Fermi GBM Observations of SGR J1935+2154
  80. GRB 210704A: OAJ T80 multi-color detections
  81. GRB 210706A: Swift-XRT afterglow detection
  82. Integral GRB210707.02: Global MASTER-Net observations report
  83. GRB 210706A: Swift ToO observations
  84. Fermi trigger No 647252274: Global MASTER-Net observations report
  85. Integral GRB210706.72: Global MASTER-Net observations report
  86. GRB 210706A: Swift/BAT-GUANO detection and arcminute localization
  87. GRB 210704A: CAHA 2.2m Afterglow Detection
  88. GRB 210704A: RATIR optical upper limits
  89. GRB 210704A: Swift/UVOT Upper Limits
  90. Konus-Wind detection of GRB 210704A
  91. GRB 210619B: ALMA detection
  92. GRB 210704A: Assy optical afterglow candidate
  93. GRB 210704A: possible local hosts
  94. GRB 210704A: Swift-XRT afterglow detection
  95. IceCube-210510A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  96. GRB 210704A: Swift ToO observations
  97. Fermi trigger No 647108723: Global MASTER-Net observations report
  98. Fermi trigger No 647120009: Global MASTER-Net observations report
  99. GRB 210702A: BOOTES-3/YA optical counterpart observations
  100. Konus-Wind detection of GRB 210702A

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