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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"

21116 results found.

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

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