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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"

21118 results found.

  1. GRB 210730A: Tautenburg observations
  2. GRB 210807A: Tautenburg observations
  3. IceCube Alert 210811.09: Global MASTER-Net observations report
  4. GRB 210807A: Detection by GRBAlpha
  5. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  6. GRB 210807C: Swift/UVOT Upper Limits
  7. GRB 210807A: Swift/UVOT Detection
  8. GRB 210807A: correction to the GCN Circ. #30614 Assy optical observations
  9. GRB 210610B: Assy optical observations
  10. Swift GRB210807.74: Global MASTER-Net observations report
  11. Fermi GRB 210807C: Global MASTER-Net observations report
  12. Swift GRB210807.96: Global MASTER-Net observations report
  13. Fermi GRB 210807B: Global MASTER-Net observations report
  14. Swift GRB 210807A: Global MASTER-Net observations report
  15. Swift GRB210807.79: Global MASTER-Net observations report
  16. Swift GRB210807.78: Global MASTER-Net observations report
  17. Fermi trigger No 650046564: Global MASTER-Net observations report
  18. Fermi trigger No 649814537: Global MASTER-Net observations report
  19. Fermi trigger No 649684549: Global MASTER-Net observations report
  20. GRB 210802A: Swift-XRT afterglow detection
  21. GRB 210802A: Tiled Swift observations
  22. Fermi trigger No 649627691: Global MASTER-Net observations report
  23. GRB 210731A: continued GROND observations
  24. GRB 210731A: VLT/X-shooter redshift
  25. Fermi trigger No 649524889: Global MASTER-Net observations report
  26. Fermi trigger No 649519043: Global MASTER-Net observations report
  27. GRB 210731A: GROND observations
  28. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  29. Swift GRB210731.62: Global MASTER-Net observations report
  30. GRB 210731A: MeerLICHT optical afterglow detection
  31. Swift GRB210731.93: Global MASTER-Net observations report
  32. Fermi-LAT Gamma-ray Observations of IceCube-210730A
  33. GRB 210730A: Campo Imperatore optical observations
  34. Swift GRB 210730A: Global MASTER-Net observations report
  35. Fermi trigger No 649390368: Global MASTER-Net observations report
  36. GRB 210730A: TNG optical observations
  37. GRB 210726A: Chandra detection of the X-ray afterglow
  38. Fermi trigger No 649313854: Global MASTER-Net observations report
  39. GRB 210730A: Swift/UVOT Upper Limits
  40. GRB 210726A: OSIRIS/GTC observations
  41. GRB 210726A: 6 GHz VLA radio upper limit
  42. GRB 210702A: MeerKAT radio detection
  43. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  44. Fermi trigger No 649072251: Global MASTER-Net observations report
  45. GRB 210725A: AbAO optical upper limit
  46. GRB 210724A: Swift/UVOT Upper Limits
  47. GRB 210723A: Swift/UVOT Upper Limits
  48. GRB 210725A: Swift/UVOT Upper Limits
  49. GRB 210725B: Swift/UVOT Upper Limits
  50. Swift GRB210726.80: Global MASTER-Net observations report
  51. Fermi trigger No 648959581: Global MASTER-Net observations report
  52. Swift GRB 210725B: Global MASTER-Net observations report
  53. GRB 210724A: Afterglow candidate from OSIRIS/GTC
  54. GRB 210722A: continued Assy optical observations
  55. GRB 210722A: Nanshan/NEXT further optical observations
  56. Fermi trigger No 648868114: Global MASTER-Net observations report
  57. Swift GRB210725.16: Global MASTER-Net observations report
  58. GRB210724A: MeerLICHT upper limits
  59. Swift GRB210724.84: Global MASTER-Net observations report
  60. GRB 210722A: continued Assy optical observations
  61. Swift GRB 210723A: Global MASTER-Net observations report
  62. GRB 210722A: Kitab optical observations, light curve
  63. GRB 210722A: Redshift from OSIRIS/GTC
  64. GRB 210722A: RATIR Optical Observations
  65. GRB 210722A: Swift/UVOT Detection
  66. GRB 210722A: GIT optical detection and preliminary analysis
  67. Swift GRB 210722A: Global MASTER-Net observations report
  68. GRB 210702A: ALMA detection of mm-band rebrightening
  69. GRB 210702A: ATCA detection of radio rebrightening
  70. GRB 210722A: Nanshan/NEXT optical afterglow observations
  71. Fermi trigger No 648602917: Global MASTER-Net observations report
  72. Fermi-LAT Gamma-ray Observations of IceCube-210717A
  73. Fermi trigger No 648359752: Global MASTER-Net observations report
  74. Fermi trigger No 648278666: Global MASTER-Net observations report
  75. Fermi trigger No 647942198: MASTER optical afterglow detection
  76. GRB 210704A: Zeiss-1000/SAO-RAS optical observations
  77. Fermi trigger No 648033323: Global MASTER-Net observations report
  78. Fermi trigger No 648024201: Global MASTER-Net observations report
  79. Fermi trigger No 647942198: Global MASTER-Net observations report
  80. GRB 210712A: Swift/UVOT Upper Limits
  81. GRB 210712A: BOOTES-3/YA optical upper limit
  82. Fermi trigger No 647805873: Global MASTER-Net observations report
  83. GRB 210704A: Lowell Discovery Telescope Optical Observations
  84. Fermi trigger No 647775795: Global MASTER-Net observations report
  85. GRB 210704A: Continued Gemini-North NIR K-band Detections
  86. GRB 210704A: INTEGRAL observations
  87. GRB 210704A: NOT optical observations and color change
  88. GRB210704A: Gemini near-infrared upper limits
  89. Fermi trigger No 647653174: Global MASTER-Net observations report
  90. GRB 210704A: Assy optical afterglow upper limit
  91. Fermi trigger No 647641569: Global MASTER-Net observations report
  92. Fermi trigger No 647624281: Global MASTER-Net observations report
  93. GRB 210704A: OSIRIS/GTC Observations and Archival Detection of the Possible Host Galaxy
  94. MAXI GRB210709.93: Global MASTER-Net observations report
  95. Fermi trigger No 647522278: Global MASTER-Net observations report
  96. GRB 210704A: Gemini-North Infrared Source Detection
  97. GRB 210704A: further TNG optical observations
  98. GRB 210706A: Swift/XRT afterglow confirmation
  99. Fermi GRB 210709A: Global MASTER-Net observations report
  100. Swift GRB 210708B: Global MASTER-Net observations report

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