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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"

28726 results found.

  1. GRB 220627A: Swift/UVOT Upper Limits
  2. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  3. IceCube-220629A: No significant detection in HAWC
  4. IceCube-220629A - IceCube observation of a high-energy neutrino candidate track-like event
  5. IceCube-220627A: No significant detection in HAWC
  6. GRB 220627A: Swift-XRT afterglow detection
  7. Konus-Wind detection of GRB 220627A
  8. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  9. GRB 220627A: VLT MUSE redshift
  10. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  11. GRB 220627A: MeerLICHT candidate optical afterglow
  12. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  13. GRB 220627A: Swift/BAT-GUANO detection outside the coded FOV
  14. Konus-Wind detection of GRB 220624A
  15. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  16. GRB 220627A: Swift ToO observations
  17. GRB 220627A: Fermi-LAT detection
  18. GRB 220627A: MeerLICHT detection of two afterglow candidates
  19. Fermi GRB 220627A: Global MASTER-Net observations report
  20. IceCube-Cascade 220625A: Upper limits from a search for additional neutrino events in IceCube
  21. IceCube-220624A: No significant detection in HAWC
  22. GRB 220623A: GIT optical upper limits.
  23. GRB 220624A: CALET Gamma-Ray Burst Monitor detection
  24. GRB 220623A: T193-OHP optical upper limit
  25. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  26. GRB 220624A: Fermi GBM Detection
  27. Fermi GRB 220623B: Global MASTER-Net observations report
  28. Fermi GRB 220624A: Global MASTER-Net observations report
  29. IPN triangulation of GRB 220624A
  30. GRB 220623A: Swift-BAT refined analysis
  31. GRB 220624A: Swift/BAT-GUANO detection outside the coded FOV
  32. GRB 220611A: X-ray afterglow Chandra sub-arcsecond localization
  33. GRB 220624A: AGILE/GRID analysis
  34. GRB 220624A: AGILE detection
  35. Konus-Wind detection of GRB 220623A
  36. GRB 220623A: AbAO optical upper limit
  37. GRB 220623A: Swift-XRT refined Analysis
  38. GRB 220623A: NOT optical observations
  39. GRB 220623A: Swift/UVOT Upper Limits
  40. Konus-Wind detection of GRB 220609B
  41. GRB 220623A: AGILE detection
  42. GRB 220623A: AstroSat CZTI detection
  43. GRB 220623A: iTelescope optical upper limit
  44. GRB 220618A: Fermi GBM detection
  45. Swift Detection of MAXI J0655-013
  46. GRB 220618A: Swift-BAT refined analysis
  47. GRB 220618A: iTelescope T-19 upper limit
  48. Konus-Wind detection of GRB 220617A
  49. Fermi GRB 220620B: Global MASTER-Net observations report
  50. Fermi GRB 220620A: Global MASTER-Net observations report
  51. GRB 220611A: Continued Gemini Infrared Observations
  52. GRB 220617A: TNG optical observations
  53. GRB 220617A: Fermi GBM observation
  54. GRB 220611A optical counterpart
  55. GRB 220618A: Swift-XRT refined Analysis
  56. IPN triangulation of GRB 220617A (short)
  57. GRB 220618A: Swift/UVOT Upper Limits
  58. GRB220611A: Gemini Optical Afterglow Confirmation
  59. GRB 220617A: Swift-XRT observations
  60. GRB 220617A: Fermi-LAT detection
  61. GRB 220617B: Swift ToO observations
  62. Fermi GRB 220617A: Global MASTER-Net observations report
  63. GRB 220611A: Gemini Ks counterpart detection
  64. Konus-Wind detection of GRB 220613A
  65. IPN triangulation of GRB 220613A
  66. GRB 220611A: Gemini South Infrared Detection
  67. IPN triangulation of GRB 220606C
  68. GRB 220611A: Swift/UVOT Upper Limits
  69. GRB 220612A: CALET Gamma-Ray Burst Monitor detection
  70. GRB 220611A: Swift-BAT refined analysis
  71. Swift GRB 220611A: Global MASTER-Net observations report
  72. GRB 220611A: Swift-XRT refined Analysis
  73. IPN triangulation of GRB 220609B
  74. Fermi GRB 220610A: Global MASTER-Net observations report
  75. GRB 220609B: AstroSat CZTI detection
  76. GRB 220608A: AstroSat CZTI detection
  77. GRB 220606A: Fermi GBM observation
  78. Fermi GRB 220608A: Global MASTER-Net observations report
  79. GRB 220606B: Gemini South Optical Observations
  80. GRB 220606B: Fermi GBM Observation
  81. GRB 220606B: Swift follow-up observations
  82. Konus-Wind detection of GRB 220601A
  83. GRB 220606A: Swift/BAT-GUANO detection
  84. GRB 220606B: GUANO coordinate correction to GCN 32167
  85. GRB 220527A: A BdHN I with a clear UPE phase
  86. GRB 220606B: Swift ToO observations
  87. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  88. Fermi GRB 220606B: Global MASTER-Net observations report
  89. IPN triangulation of GRB 220601A (long)
  90. Fermi-GBM will trial new SAA regions from Tuesday June 7th
  91. GRB 220527A: MITSuME Akeno continued optical observation
  92. GRB 220527A: Lick 3m Optical Observations
  93. Konus-Wind detection of GRB 220528A
  94. IPN triangulation of GRB 220528A (short)
  95. GRB 220528A: Fermi GBM Observation
  96. Fermi GRB 220530A: Global MASTER-Net observations report
  97. Konus-Wind observation of GRB 220527A
  98. Correction to GCN 32148: Should be GRB 220528A
  99. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  100. GRB 220527A: AST3-3 Yaoan Optical Observation

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