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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

3104 results found.

  1. GRB 220518A: Swift/UVOT Detection
  2. GRB 220514A: MITSuME Akeno optical observation
  3. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  4. IceCube Alert 220513.97: Global MASTER-Net observations report
  5. Fermi GRB 220513A: Global MASTER-Net observations report
  6. GRB 220511A: Swift/BAT-GUANO arcminute localization
  7. Fermi trigger No 673846271: Global MASTER-Net observations report
  8. GRB 220506A: MITSuME Akeno optical upper limits
  9. GRB 220506A: GIT optical upper limit.
  10. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  11. IPN triangulation of GRB 220423A
  12. IceCube-220501A: No Candidate Counterparts from the Zwicky Transient Facility
  13. IceCube Alert 220501.95: Global MASTER-Net observations report
  14. GRB 220426A: Swift-XRT and UVOT observations
  15. Konus-Wind detection of GRB 220426A
  16. Fermi trigger No 672492774: Global MASTER-Net observations report
  17. GRB 220421B: Detection by VZLUSAT-2
  18. Fermi GRB 220417A: Global MASTER-Net observations report
  19. Fermi trigger No 671729344: Global MASTER-Net observations report
  20. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  21. GRB 220408A: KAIT Optical Observations
  22. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  23. IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
  24. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  25. GRB 220404A: Swift-BAT refined analysis
  26. GRB 220404B: Fermi GBM Final Real-time Localization
  27. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  28. Fermi GRB 220330A: Global MASTER-Net observations report
  29. GRB220319A: Optical observations from NOT
  30. IceCube-220317A: MASTER Global Robotic Net optical observations
  31. GRB 220315A: Fermi GBM Final Real-time Localization
  32. GRB 220308A: AGILE detection
  33. GRB 220310A: MAXI/GSC detection
  34. Fermi GRB 220309A: Global MASTER-Net observations report
  35. IPN triangulation of GRB 220305B
  36. Fermi trigger No 666962499: Global MASTER-Net observations report
  37. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  38. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  39. Fermi GRB 220209A: Global MASTER-Net observations report
  40. Konus-Wind detection of GRB 220128A
  41. Fermi GRB 220131A: Global MASTER-Net observations report
  42. GRB 220117C: Swift/BAT-GUANO arcminute localization
  43. Fermi trigger No 663966693: Global MASTER-Net observations report
  44. Fermi GRB 220111A: Global MASTER-Net observations report
  45. Fermi trigger No 663406755: Global MASTER-Net observations report
  46. GRB 220101A: TNG NIR afterglow detection
  47. Fermi trigger No 662768315: Global MASTER-Net observations report
  48. Fermi trigger No 662084433: Global MASTER-Net observations report
  49. GRB 211222A: Fermi GBM Final Real-time Localization
  50. GRB 211218A: MITSuME Akeno optical upper limits
  51. GRB 211106A: XMM-Newton monitoring campaign detections
  52. Fermi GRB 211216A: Global MASTER-Net observations report
  53. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  54. Fermi GRB 211212B: Global MASTER-Net observations report
  55. Fermi GRB 211211B: Global MASTER-Net observations report
  56. Fermi trigger No 660868196: Global MASTER-Net observations report
  57. Fermi trigger No 660736561: Global MASTER-Net observations report
  58. Fermi GRB 211204C: Global MASTER-Net observations report
  59. GRB 211204C: Fermi GBM Final Real-time Localization
  60. Fermi GRB 211204B: Global MASTER-Net observations report
  61. GRB 211129A: Enhanced Swift-XRT position
  62. IPN triangulation of GRB 211118A
  63. GRB 211129A: Swift detection of a burst
  64. GRB 211120548: Fermi GBM observation
  65. IceCube Alert 211125.27: Global MASTER-Net observations report
  66. Fermi trigger No 659106591: Global MASTER-Net observations report
  67. Fermi trigger No 658971499: Global MASTER-Net observations report
  68. IceCube-211116A: No neutrino counterpart detected with ANTARES
  69. Fermi trigger No 658755664: Global MASTER-Net observations report
  70. Fermi trigger No 658764238: Global MASTER-Net observations report
  71. Fermi GRB 211112A: Global MASTER-Net observations report
  72. Fermi trigger No 658214822: Global MASTER-Net observations report
  73. GRB 211109B: Fermi GBM Final Real-time Localization
  74. GRB 211023B: MITSuME Akeno optical upper limits
  75. GRB 211102A: Fermi GBM Final Real-time Localization
  76. Fermi GRB 211031A: Global MASTER-Net observations report
  77. IPN triangulation of GRB 211022A
  78. GRB 211023A: continued Mondy optical observations
  79. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  80. Fermi GRB 211027A: Global MASTER-Net observations report
  81. GRB211023A: optical afterglow detection from Konkoly Observatory
  82. Swift GRB 211023B: Global MASTER-Net observations report
  83. Fermi GRB 211024A: Global MASTER-Net observations report
  84. GRB 211022A: GECAM detection
  85. GRB 211019A: Fermi GBM Final Real-time Localization
  86. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  87. Fermi trigger No 655646385: Global MASTER-Net observations report
  88. Swift GRB211001.03: Global MASTER-Net observations report
  89. Fermi trigger No 654658271: Global MASTER-Net observations report
  90. Fermi GRB 210929B: Global MASTER-Net observations report
  91. GRB 210927A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 654396242)
  92. GRB 210919A: iTelescope T-11 upper limits
  93. IceCube-210922A: No Candidate Counterparts from the Zwicky Transient Facility
  94. IceCube Alert 210922.76: Global MASTER-Net observations report
  95. Swift GRB 210919A: Global MASTER-Net observations report
  96. GRB 210917A: Fermi GBM Final Real-time Localization
  97. AGILE observations of two bright bursts from SGR 1935+2154
  98. Fermi trigger No 653083551: Global MASTER-Net observations report
  99. Fermi trigger No 653066130: Global MASTER-Net observations report
  100. Fermi trigger No 653049776: Global MASTER-Net observations report

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