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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

19726 results found.

  1. GRB 220715B: Enhanced Swift-XRT position
  2. GRB 220715B: Swift detection of a burst
  3. GRB 220714B: LCO Optical Observations
  4. GRB 220714B: Enhanced Swift-XRT position
  5. GRB 220714B: Swift detection of a burst
  6. GRB 220710A: Swift/UVOT Upper Limits
  7. GRB 220711B: 10.4 m GTC(+EMIR) observations
  8. GRB 220711B: 10.4 m GTC(+EMIR) observations
  9. GRB 220711B, GROND observations
  10. GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  11. GRB 220711B: GIT optical upper limits
  12. GRB 220712B: NOT optical afterglow confirmation
  13. GRB 220710A: Swift ToO observations
  14. IPN triangulation of GRB 220711C (short)
  15. GRB 220711B: Swift-XRT refined Analysis
  16. GRB 220711B: Swift/UVOT Upper Limits
  17. GRB 220711B: Enhanced Swift-XRT position
  18. GRB 220711B: Fermi GBM Detection
  19. GRB 220711B: NOT optical observations
  20. GRB 220711B: LCO Optical Upper Limits
  21. GRB 220711B: Swift detection of a burst
  22. GRB 220708B: GIT optical upper limits
  23. GRB 220708B: T193-OHP optical upper limit
  24. GRB 220708B: CALET Gamma-Ray Burst Monitor detection
  25. GRB 220708B: Nanshan/NEXT optical upper limits
  26. GRB 220708A: Swift/UVOT Upper Limits
  27. GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
  28. GRB 220706A: Swift/UVOT Upper Limits
  29. GRB 220708A: Enhanced Swift-XRT position
  30. GRB 220708B: Swift ToO observations
  31. GRB 220708A: Swift-XRT observations
  32. GRB 220706A: LCO Optical Upper Limits
  33. GRB 220706A: Swift-XRT refined Analysis
  34. GRB 220706A, GROND observations
  35. GRB 220706A: Optical observations from NOT
  36. GRB 220706A: Nanshan/NEXT optical upper limits
  37. GRB 220706A: Enhanced Swift-XRT position
  38. GRB 220706A: Zadko observatory - Gingin optical observations
  39. GRB 220706A: Swift detection of a burst
  40. GRB 220701A: Swift-BAT refined analysis
  41. GRB220408A: VIRT Optical Upper Limit
  42. GRB220412A: VIRT Optical Upper Limit
  43. GRB220701A: VIRT Optical Upper Limit
  44. GRB 220701A: MITSuME Akeno optical upper limits
  45. Alert from the HAWC Burst Monitor HAWC-220702A
  46. GRB 220701A: COATLI Optical Upper Limit
  47. GRB 220701A: AbAO optical upper limit
  48. GRB 220701A: Keck/LRIS Optical Upper Limit
  49. GRB 220701A: LCO Optical Upper Limits
  50. GRB 220701A: Swift/UVOT Upper Limits
  51. GRB 220701A: Enhanced Swift-XRT position
  52. GRB 220701A: Swift detection of a burst
  53. Fermi-LAT Gamma-ray Observations of IceCube-220629A
  54. GRB 220627A, GROND observations
  55. GRB 220627A: Swift/UVOT Upper Limits
  56. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  57. IceCube-220629A: No significant detection in HAWC
  58. IceCube-220627A: No significant detection in HAWC
  59. GRB 220627A: Swift-XRT afterglow detection
  60. GRB 220627A: VLT MUSE redshift
  61. GRB 220627A: MeerLICHT candidate optical afterglow
  62. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  63. GRB 220627A: Swift ToO observations
  64. GRB 220627A: MeerLICHT detection of two afterglow candidates
  65. IceCube-220624A: No significant detection in HAWC
  66. GRB 220623A: GIT optical upper limits.
  67. GRB 220623A: T193-OHP optical upper limit
  68. GRB 220624A: Fermi GBM Detection
  69. IPN triangulation of GRB 220624A
  70. GRB 220624A: AGILE/GRID analysis
  71. GRB 220623A: AbAO optical upper limit
  72. GRB 220623A: NOT optical observations
  73. GRB 220623A: Swift/UVOT Upper Limits
  74. GRB 220623A: Enhanced Swift-XRT position
  75. GRB 220623A: AstroSat CZTI detection
  76. GRB 220623A: iTelescope optical upper limit
  77. GRB 220623A: Swift-XRT observations
  78. GRB 220618A: Fermi GBM detection
  79. GRB 220618A: iTelescope T-19 upper limit
  80. GRB 220617A: TNG optical observations
  81. GRB 220618A: Swift/UVOT Upper Limits
  82. GRB 220618A: Enhanced Swift-XRT position
  83. GRB 220618A: Swift detection of a burst
  84. GRB 220617B: Swift ToO observations
  85. GRB 220611A: Gemini Ks counterpart detection
  86. GRB 220611A: Swift/UVOT Upper Limits
  87. GRB 220610B: AstroSat CZTI detection
  88. GRB 220611A: Enhanced Swift-XRT position
  89. GRB 220611A: Swift detection of a burst
  90. GRB 220608A: Fermi GBM Final Real-time Localization
  91. GRB 220606B: Gemini South Optical Observations
  92. GRB 220527A: A BdHN I with a clear UPE phase
  93. GRB 220606B: Swift ToO observations
  94. GRB 220527A: MITSuME Akeno continued optical observation
  95. GRB 220527A: Lick 3m Optical Observations
  96. IPN triangulation of GRB 220528A (short)
  97. GRB 220527A: REM optical/NIR observations
  98. GRB 220527A: MeerLICHT afterglow observations
  99. GRB 220527A: NOT optical photometry and spectroscopic redshift
  100. GRB 220527A: MITSuME Akeno optical observation

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