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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"

3119 results found.

  1. MAXI GRB220607.41: Global MASTER-Net observations report
  2. Fermi trigger No 675992935: Global MASTER-Net observations report
  3. IPN triangulation of GRB 220528A (short)
  4. Fermi GRB 220530A: Global MASTER-Net observations report
  5. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  6. Fermi trigger No 675411172: Global MASTER-Net observations report
  7. IPN triangulation of GRB 220524B
  8. IPN triangulation of GRB 220522B
  9. GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
  10. Fermi GRB 220518B: Global MASTER-Net observations report
  11. GRB 220518A: Swift/UVOT Detection
  12. GRB 220514A: MITSuME Akeno optical observation
  13. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  14. IceCube Alert 220513.97: Global MASTER-Net observations report
  15. Fermi GRB 220513A: Global MASTER-Net observations report
  16. GRB 220511A: Swift/BAT-GUANO arcminute localization
  17. Fermi trigger No 673846271: Global MASTER-Net observations report
  18. GRB 220506A: MITSuME Akeno optical upper limits
  19. GRB 220506A: GIT optical upper limit.
  20. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  21. IPN triangulation of GRB 220423A
  22. IceCube-220501A: No Candidate Counterparts from the Zwicky Transient Facility
  23. IceCube Alert 220501.95: Global MASTER-Net observations report
  24. GRB 220426A: Swift-XRT and UVOT observations
  25. Konus-Wind detection of GRB 220426A
  26. Fermi trigger No 672492774: Global MASTER-Net observations report
  27. GRB 220421B: Detection by VZLUSAT-2
  28. Fermi GRB 220417A: Global MASTER-Net observations report
  29. Fermi trigger No 671729344: Global MASTER-Net observations report
  30. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  31. GRB 220408A: KAIT Optical Observations
  32. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  33. IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
  34. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  35. GRB 220404A: Swift-BAT refined analysis
  36. GRB 220404B: Fermi GBM Final Real-time Localization
  37. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  38. Fermi GRB 220330A: Global MASTER-Net observations report
  39. GRB220319A: Optical observations from NOT
  40. IceCube-220317A: MASTER Global Robotic Net optical observations
  41. GRB 220315A: Fermi GBM Final Real-time Localization
  42. GRB 220308A: AGILE detection
  43. GRB 220310A: MAXI/GSC detection
  44. Fermi GRB 220309A: Global MASTER-Net observations report
  45. IPN triangulation of GRB 220305B
  46. Fermi trigger No 666962499: Global MASTER-Net observations report
  47. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  48. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  49. Fermi GRB 220209A: Global MASTER-Net observations report
  50. Konus-Wind detection of GRB 220128A
  51. Fermi GRB 220131A: Global MASTER-Net observations report
  52. GRB 220117C: Swift/BAT-GUANO arcminute localization
  53. Fermi trigger No 663966693: Global MASTER-Net observations report
  54. Fermi GRB 220111A: Global MASTER-Net observations report
  55. Fermi trigger No 663406755: Global MASTER-Net observations report
  56. GRB 220101A: TNG NIR afterglow detection
  57. Fermi trigger No 662768315: Global MASTER-Net observations report
  58. Fermi trigger No 662084433: Global MASTER-Net observations report
  59. GRB 211222A: Fermi GBM Final Real-time Localization
  60. GRB 211218A: MITSuME Akeno optical upper limits
  61. GRB 211106A: XMM-Newton monitoring campaign detections
  62. Fermi GRB 211216A: Global MASTER-Net observations report
  63. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  64. Fermi GRB 211212B: Global MASTER-Net observations report
  65. Fermi GRB 211211B: Global MASTER-Net observations report
  66. Fermi trigger No 660868196: Global MASTER-Net observations report
  67. Fermi trigger No 660736561: Global MASTER-Net observations report
  68. Fermi GRB 211204C: Global MASTER-Net observations report
  69. GRB 211204C: Fermi GBM Final Real-time Localization
  70. Fermi GRB 211204B: Global MASTER-Net observations report
  71. GRB 211129A: Enhanced Swift-XRT position
  72. IPN triangulation of GRB 211118A
  73. GRB 211129A: Swift detection of a burst
  74. GRB 211120548: Fermi GBM observation
  75. IceCube Alert 211125.27: Global MASTER-Net observations report
  76. Fermi trigger No 659106591: Global MASTER-Net observations report
  77. Fermi trigger No 658971499: Global MASTER-Net observations report
  78. IceCube-211116A: No neutrino counterpart detected with ANTARES
  79. Fermi trigger No 658755664: Global MASTER-Net observations report
  80. Fermi trigger No 658764238: Global MASTER-Net observations report
  81. Fermi GRB 211112A: Global MASTER-Net observations report
  82. Fermi trigger No 658214822: Global MASTER-Net observations report
  83. GRB 211109B: Fermi GBM Final Real-time Localization
  84. GRB 211023B: MITSuME Akeno optical upper limits
  85. GRB 211102A: Fermi GBM Final Real-time Localization
  86. Fermi GRB 211031A: Global MASTER-Net observations report
  87. IPN triangulation of GRB 211022A
  88. GRB 211023A: continued Mondy optical observations
  89. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  90. Fermi GRB 211027A: Global MASTER-Net observations report
  91. GRB211023A: optical afterglow detection from Konkoly Observatory
  92. Swift GRB 211023B: Global MASTER-Net observations report
  93. Fermi GRB 211024A: Global MASTER-Net observations report
  94. GRB 211022A: GECAM detection
  95. GRB 211019A: Fermi GBM Final Real-time Localization
  96. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  97. Fermi trigger No 655646385: Global MASTER-Net observations report
  98. Swift GRB211001.03: Global MASTER-Net observations report
  99. Fermi trigger No 654658271: Global MASTER-Net observations report
  100. Fermi GRB 210929B: Global MASTER-Net observations report

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