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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"

21113 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-220115A and detection of a new gamma-ray source, Fermi J2350.2+2620
  2. GRB 220117B: Nanshan/NEXT optical upper limit
  3. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  4. Swift GRB 220117A: Global MASTER-Net observations report
  5. Swift GRB 220117B: Global MASTER-Net observations report
  6. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  7. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  8. GECAM observations of a series of bursts from SGR J1935+2154
  9. Fermi trigger No 663960124: Global MASTER-Net observations report
  10. Fermi trigger No 663967527: Global MASTER-Net observations report
  11. Fermi trigger No 663923149: Global MASTER-Net observations report
  12. Fermi trigger No 663899819: Global MASTER-Net observations report
  13. Fermi trigger No 663886592: Global MASTER-Net observations report
  14. Fermi trigger No 663966693: Global MASTER-Net observations report
  15. IceCube Alert 220115.51: Global MASTER-Net observations report
  16. Fermi trigger No 663927396: Global MASTER-Net observations report
  17. Fermi trigger No 663921434: Global MASTER-Net observations report
  18. GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
  19. GECAM observations of a series of bursts from SGR J1935+2154
  20. Fermi trigger No 663763320: Global MASTER-Net observations report
  21. Fermi trigger No 663710289: Global MASTER-Net observations report
  22. Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
  23. AGILE observations of a burst from SGR 1935+2154
  24. GECAM observations of a series of bursts from SGR J1935+2154
  25. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  26. Fermi trigger No 663669570: Global MASTER-Net observations report
  27. Fermi trigger No 663658976: Global MASTER-Net observations report
  28. Fermi trigger No 663618072: Global MASTER-Net observations report
  29. Fermi GRB 220111A: Global MASTER-Net observations report
  30. GRB 220107A: SAO RAS optical observations
  31. GECAM observations of a series of bursts from SGR J1935+2154
  32. GRB 220107A: further SAO RAS optical observations
  33. Fermi trigger No 663406755: Global MASTER-Net observations report
  34. GRB 220107A: SAO RAS optical observations
  35. GRB 220101A: SAO RAS optical observations
  36. GRB 220107A: AbAO and Terskol optical observations
  37. GRB 220107A: Nanshan/NEXT optical observations
  38. GRB 220107A: Swift/UVOT Detection
  39. GRB 220107B: Fermi GBM observations
  40. GRB 220107B: Swift-XRT afterglow detection
  41. GRB 220107A: Swift-XRT afterglow detection
  42. GRB 220107B: Tiled Swift observations
  43. GRB 220107A: Fermi GBM observations
  44. Fermi trigger No 663274898: Global MASTER-Net observations report
  45. GRB 220107A: Swift ToO observations
  46. Fermi GRB 220107A: Global MASTER-Net observations report
  47. GRB 220107A: Swift/BAT-GUANO arcminute localization
  48. GRB 220101A: Tautenburg observations
  49. GRB 220101A: Continued Mondy optical observations
  50. GRB 220101A: further TNG NIR observations
  51. GRB 220101A: continued 1.3m DFOT Optical Observations
  52. Fermi trigger No 663129379: Global MASTER-Net observations report
  53. GECAM observations of a series of bursts from SGR J1935+2154
  54. GRB 220101A: Mondy optical observations
  55. GRB 220101A: 3rd LCO Optical Observation
  56. GRB 220101A: iTelescope optical observations
  57. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  58. GRB 220101A: VLA detection
  59. GRB 220101A: 1.3m DFOT observations
  60. GRB 220101A: LCO Continued Optical Observations
  61. Fermi GRB 220104A: Global MASTER-Net observations report
  62. Fermi GRB 220103A: Global MASTER-Net observations report
  63. GRB 211227A: Gemini South Optical Observations
  64. Alert from the HAWC Burst Monitor HAWC-220103A
  65. GRB 220101A: ALMA detection
  66. GRB 220101A: LCO Optical Observations
  67. GRB 220101A: Tautenburg observations
  68. GRB 220101A: GMG observation (2nd epoch)
  69. GRB 220101A: OASDG optical observations
  70. GRB 220101A: GMG observation
  71. Fermi trigger No 662768315: Global MASTER-Net observations report
  72. GRB 220101A: THO optical observations
  73. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  74. Swift GRB220101.22: Global MASTER-Net observations report
  75. GRB 220101: Swift/UVOT Detection
  76. GRB 211229A: Swift-XRT and UVOT observations
  77. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  78. Fermi GRB 211229B: Global MASTER-Net observations report
  79. GRB 211229A: Swift ToO observations
  80. GRB 211229A: Swift/BAT-GUANO arcminute localization
  81. Fermi GRB 211229A: Global MASTER-Net observations report
  82. GRB 211227A: Swift/UVOT Upper Limits
  83. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  84. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  85. GRB 211227A: LCO Optical Observations
  86. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  87. GRB 211221A: Swift/UVOT Upper Limits
  88. Swift GRB211227.98: Global MASTER-Net observations report
  89. IceCube-20211216B: observations of SN2021gpw in the errorbox of the neutrino trigger
  90. Fermi trigger No 662216114: Global MASTER-Net observations report
  91. GRB 211225A: MITSuME Akeno optical upper limits
  92. Swift GRB 211225B: Global MASTER-Net observations report
  93. Fermi GRB 211225C: Global MASTER-Net observations report
  94. MAXI GRB211225.14: Global MASTER-Net observations report
  95. Fermi trigger No 662084433: Global MASTER-Net observations report
  96. GRB 211106A: Third HST Observation
  97. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  98. Fermi trigger No 662010159: Global MASTER-Net observations report
  99. AGILE observations of a bright burst from SGR 1935+2154
  100. Swift GRB 211223C: Global MASTER-Net observations report

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