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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"

28098 results found.

  1. Swift GRB221009.59: Global MASTER-Net OT detection
  2. GRB 221008A: Swift-XRT observations
  3. Swift J1913.1+1946 a new bright hard X-ray and optical transient
  4. GRB 221008A: MAXI/GSC detection
  5. GRB 221006A: Swift-XRT observations
  6. GRB 221006A: MAXI/GSC detection
  7. GRB 220930A: MITSuME Akeno optical upper limits
  8. GRB 220912A: Detection by VZLUSAT-2
  9. Fermi trigger No 686588176: Global MASTER-Net observations report
  10. Fermi GBM trigger 686350260/221001869 is not a GRB
  11. GRB 220930A: AbAO Optical Upper Limit
  12. GRB 220930A: Swift-BAT refined analysis
  13. GRB 220930A: Swift-XRT refined Analysis
  14. GRB 220930A: LCOGT Optical Upper Limits
  15. GRB 220930A: Swift/UVOT Upper Limits
  16. GRB 220930A: Enhanced Swift-XRT position
  17. GRB 220930A: COATLI Upper Limits
  18. GRB 220930A: Swift detection of a burst
  19. Fermi-LAT gamma-ray observations of IceCube-220928A
  20. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  21. IPN triangulation of GRB 220927A (long)
  22. GRB 220921A: LCOGT Optical Observations
  23. GRB 220927A: Fermi GBM Final Localization
  24. GRB 220924A: Fermi GBM detection
  25. Ultra-long GRB 220525B: Konus-Wind and Fermi-GBM detection
  26. Swift Trigger 1125354 (GRB 220926A) is not a GRB
  27. Analysis of long GRB 220926B detected by INTEGRAL
  28. GRB 220926A: Swift detection of a burst
  29. GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
  30. GRB 220921A: further MeerLICHT observations
  31. GRB 220921A: DDOTI Detection of the Afterglow
  32. GRB 220921A: Fermi GBM detection
  33. GRB 220921A: MeerLICHT afterglow observations
  34. GRB 220921A: Swift-XRT Observations
  35. GRB 220921A: Fermi-LAT detection
  36. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  37. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  38. Fermi trigger No 684894705: Global MASTER-Net observations report
  39. IceCube-220907A: No significant detection in HAWC
  40. GRB 220909A: Fermi GBM observation
  41. GRB 220910A: Fermi GBM observation
  42. GRB 220909A: Swift-XRT observations
  43. IPN triangulation of GRB 220905A
  44. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
  45. IceCube-220907A: Upper limits from a search for additional neutrino events in IceCube
  46. GRB 220907A: Swift-BAT refined analysis
  47. IPN triangulation of GRB 220903A (long)
  48. GRB 220907A: Fermi GBM observation
  49. GRB 220907A: Nanshan/NEXT optical upper limits
  50. GRB 220907A: Swift/UVOT Upper Limits
  51. GRB 220907A: Swift-XRT refined Analysis
  52. Fermi-LAT Gamma-ray Observations of IceCube-220907A
  53. GRB 220907A: Swift detection of a burst
  54. Swift GRB220907.59: Global MASTER-Net observations report
  55. GRB 220905A: BALROG localization (Fermi Trigger 684070128 / GRB 220905478)
  56. GRB 220831A: DECam detection of a possible optical counterpart
  57. GRB 220831A: Fermi GBM observation
  58. GRB 220831A: Swift-XRT observations
  59. GRB 220831A: Swift/BAT-GUANO localization of a short burst
  60. IceCube-220822A: No significant detection in HAWC
  61. Fermi trigger No 683476673: Global MASTER-Net observations report
  62. IceCube-Cascade 220826A: Upper limits from a search for additional neutrino events in IceCube
  63. GRB 220826A: Swift-BAT refined analysis
  64. GRB 220826A: Fermi GBM observation
  65. GRB 220826A: Swift-XRT refined Analysis
  66. GRB 220825A: Fermi GBM observation
  67. GRB 220826A: Lesedi optical afterglow detection
  68. GRB 220826A: Swift/UVOT Detection
  69. GRB 220826A: iTelescope optical afterglow observations
  70. GRB 220826A: Enhanced Swift-XRT position
  71. GRB 220826A: Swift detection of a burst with an optical counterpart
  72. GRB 220825A: Swift/BAT-GUANO detection
  73. IceCube-220822A: Upper limits from a search for additional neutrino events in IceCube
  74. GRB 220823A: Fermi GBM detection
  75. Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154
  76. GRB 220823A: Swift/BAT-GUANO detection of a short burst
  77. GRB 220813A: VLT optical observations and possible host galaxy
  78. GRB 220813A: Swift/UVOT Detection
  79. GRB 220810A: Further Swift-XRT observations
  80. GRB 220813A: Swift-XRT refined Analysis
  81. GRB 220813A: Enhanced Swift-XRT position
  82. GRB 220813A: Swift detection of a burst with an optical counterpart
  83. GRB 220810A: Swift-XRT observations
  84. GRB 220719B: Detection by VZLUSAT-2
  85. GRB 220810A: MeerLICHT detection of two afterglow candidates
  86. GRB 220806A: Swift-BAT refined analysis
  87. IceCube Alert 220808.33: Global MASTER-Net observations report
  88. GRB 220730A: Swift-BAT refined analysis
  89. GRB 220730A: Swift-XRT afterglow detection
  90. GRB 220730A: Swift/UVOT Upper Limits
  91. GRB 220730A: Swift-XRT observations
  92. GRB 220730A: Swift detection of a short hard burst
  93. Fermi trigger No 680421061: Global MASTER-Net observations report
  94. GRB 220715B: VIRT Optical Upper Limit
  95. Introducing new GCN Kafka broker and web site for transient alerts, https://gcn.nasa.gov
  96. GRB 220715B: Swift-BAT refined analysis
  97. GRB220714B: UVOT detections
  98. GRB 220715B: Fermi GBM detection
  99. GRB 220715B: Swift-XRT refined Analysis
  100. GRB 220715B: Swift/UVOT Upper Limits

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