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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"

2900 results found.

  1. Fermi GRB 220513A: Global MASTER-Net observations report
  2. GRB 220511A: Swift/BAT-GUANO arcminute localization
  3. Fermi trigger No 673846271: Global MASTER-Net observations report
  4. GRB 220506A: MITSuME Akeno optical upper limits
  5. GRB 220506A: GIT optical upper limit.
  6. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  7. IPN triangulation of GRB 220423A
  8. IceCube-220501A: No Candidate Counterparts from the Zwicky Transient Facility
  9. IceCube Alert 220501.95: Global MASTER-Net observations report
  10. GRB 220426A: Swift-XRT and UVOT observations
  11. Konus-Wind detection of GRB 220426A
  12. Fermi trigger No 672492774: Global MASTER-Net observations report
  13. GRB 220421B: Detection by VZLUSAT-2
  14. Fermi GRB 220417A: Global MASTER-Net observations report
  15. Fermi trigger No 671729344: Global MASTER-Net observations report
  16. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  17. GRB 220408A: KAIT Optical Observations
  18. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  19. IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
  20. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  21. GRB 220404A: Swift-BAT refined analysis
  22. GRB 220404B: Fermi GBM Final Real-time Localization
  23. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  24. Fermi GRB 220330A: Global MASTER-Net observations report
  25. GRB220319A: Optical observations from NOT
  26. IceCube-220317A: MASTER Global Robotic Net optical observations
  27. GRB 220315A: Fermi GBM Final Real-time Localization
  28. GRB 220308A: AGILE detection
  29. GRB 220310A: MAXI/GSC detection
  30. Fermi GRB 220309A: Global MASTER-Net observations report
  31. IPN triangulation of GRB 220305B
  32. Fermi trigger No 666962499: Global MASTER-Net observations report
  33. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  34. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  35. Fermi GRB 220209A: Global MASTER-Net observations report
  36. Konus-Wind detection of GRB 220128A
  37. Fermi GRB 220131A: Global MASTER-Net observations report
  38. GRB 220117C: Swift/BAT-GUANO arcminute localization
  39. Fermi trigger No 663966693: Global MASTER-Net observations report
  40. Fermi GRB 220111A: Global MASTER-Net observations report
  41. Fermi trigger No 663406755: Global MASTER-Net observations report
  42. GRB 220101A: TNG NIR afterglow detection
  43. Fermi trigger No 662768315: Global MASTER-Net observations report
  44. Fermi trigger No 662084433: Global MASTER-Net observations report
  45. GRB 211222A: Fermi GBM Final Real-time Localization
  46. GRB 211218A: MITSuME Akeno optical upper limits
  47. GRB 211106A: XMM-Newton monitoring campaign detections
  48. Fermi GRB 211216A: Global MASTER-Net observations report
  49. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  50. Fermi GRB 211212B: Global MASTER-Net observations report
  51. Fermi GRB 211211B: Global MASTER-Net observations report
  52. Fermi trigger No 660868196: Global MASTER-Net observations report
  53. Fermi trigger No 660736561: Global MASTER-Net observations report
  54. Fermi GRB 211204C: Global MASTER-Net observations report
  55. GRB 211204C: Fermi GBM Final Real-time Localization
  56. Fermi GRB 211204B: Global MASTER-Net observations report
  57. GRB 211129A: Enhanced Swift-XRT position
  58. IPN triangulation of GRB 211118A
  59. GRB 211129A: Swift detection of a burst
  60. GRB 211120548: Fermi GBM observation
  61. IceCube Alert 211125.27: Global MASTER-Net observations report
  62. Fermi trigger No 659106591: Global MASTER-Net observations report
  63. Fermi trigger No 658971499: Global MASTER-Net observations report
  64. IceCube-211116A: No neutrino counterpart detected with ANTARES
  65. Fermi trigger No 658755664: Global MASTER-Net observations report
  66. Fermi trigger No 658764238: Global MASTER-Net observations report
  67. Fermi GRB 211112A: Global MASTER-Net observations report
  68. Fermi trigger No 658214822: Global MASTER-Net observations report
  69. GRB 211109B: Fermi GBM Final Real-time Localization
  70. GRB 211023B: MITSuME Akeno optical upper limits
  71. GRB 211102A: Fermi GBM Final Real-time Localization
  72. Fermi GRB 211031A: Global MASTER-Net observations report
  73. IPN triangulation of GRB 211022A
  74. GRB 211023A: continued Mondy optical observations
  75. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  76. Fermi GRB 211027A: Global MASTER-Net observations report
  77. GRB211023A: optical afterglow detection from Konkoly Observatory
  78. Swift GRB 211023B: Global MASTER-Net observations report
  79. Fermi GRB 211024A: Global MASTER-Net observations report
  80. GRB 211022A: GECAM detection
  81. GRB 211019A: Fermi GBM Final Real-time Localization
  82. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  83. Fermi trigger No 655646385: Global MASTER-Net observations report
  84. Swift GRB211001.03: Global MASTER-Net observations report
  85. Fermi trigger No 654658271: Global MASTER-Net observations report
  86. Fermi GRB 210929B: Global MASTER-Net observations report
  87. GRB 210927A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 654396242)
  88. GRB 210919A: iTelescope T-11 upper limits
  89. IceCube-210922A: No Candidate Counterparts from the Zwicky Transient Facility
  90. IceCube Alert 210922.76: Global MASTER-Net observations report
  91. Swift GRB 210919A: Global MASTER-Net observations report
  92. GRB 210917A: Fermi GBM Final Real-time Localization
  93. AGILE observations of two bright bursts from SGR 1935+2154
  94. Fermi trigger No 653083551: Global MASTER-Net observations report
  95. Fermi trigger No 653066130: Global MASTER-Net observations report
  96. Fermi trigger No 653049776: Global MASTER-Net observations report
  97. Fermi trigger No 653010039: Global MASTER-Net observations report
  98. IPN triangulation of a bright burst from SGR 1935+2154
  99. Fermi trigger No 652927551: Global MASTER-Net observations report
  100. Fermi trigger No 652911693: Global MASTER-Net observations report

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