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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"

30484 results found.

  1. GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
  2. GRB 220711B, GROND observations
  3. Konus-Wind detection of GRB 220711C
  4. GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  5. GRB 220711B: GIT optical upper limits
  6. Fermi GRB 220711B: Global MASTER-Net observations report
  7. GRB 220712B: NOT optical afterglow confirmation
  8. GRB 220710A: Swift ToO observations
  9. GRB 220710A: Swift/BAT-GUANO arcminute localization
  10. GRB 220711B: Swift-BAT refined analysis
  11. IPN triangulation of GRB 220711C (short)
  12. GRB 220711B: Swift-XRT refined Analysis
  13. GRB 220711B: Swift/UVOT Upper Limits
  14. GRB 220711B: Fermi GBM Detection
  15. GRB 220711B: NOT optical observations
  16. GRB 220711B: LCO Optical Upper Limits
  17. GRB 220708B: GIT optical upper limits
  18. GRB 220708A: Swift-BAT refined analysis
  19. GRB 220708B: T193-OHP optical upper limit
  20. Konus-Wind detection of GRB 220708B (Correction to GCN 32358)
  21. Konus-Wind detection of GRB 220708B
  22. IceCube-220624A: Classification of AT2022nit as a type Ia supernova and AT2021bei as an AGN
  23. GRB 220708B: CALET Gamma-Ray Burst Monitor detection
  24. GRB 220708B: Nanshan/NEXT optical upper limits
  25. GRB 220708A: Swift/UVOT Upper Limits
  26. GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
  27. GRB 220708A: Swift-XRT refined Analysis
  28. GRB 220706A: Swift/UVOT Upper Limits
  29. GRB 220706A: Swift-BAT refined analysis
  30. GRB 220708B: Swift ToO observations
  31. GRB 220708B: Swift/BAT-GUANO arcminute localization
  32. GRB 220706A: LCO Optical Upper Limits
  33. GRB 220627A: ATCA detection of radio counterpart
  34. GRB 220706A: Swift-XRT refined Analysis
  35. GRB 220706A, GROND observations
  36. GRB 220706A: Optical observations from NOT
  37. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  38. GRB 220702B: AstroSat CZTI detection
  39. GRB 220706A: Nanshan/NEXT optical upper limits
  40. Swift GRB 220706A: Global MASTER-Net observations report
  41. GRB 220706A: Zadko observatory - Gingin optical observations
  42. GRB 220701A: Swift-BAT refined analysis
  43. GRB220408A: VIRT Optical Upper Limit
  44. GRB220412A: VIRT Optical Upper Limit
  45. GRB220701A: VIRT Optical Upper Limit
  46. GRB 220701A: MITSuME Akeno optical upper limits
  47. GRB 220701A: COATLI Optical Upper Limit
  48. GRB 220701A: AbAO optical upper limit
  49. GRB 220627A: AstroSat CZTI detection
  50. GRB 220701A: Keck/LRIS Optical Upper Limit
  51. GRB 220701A: Swift-XRT refined Analysis
  52. GRB 220701A: LCO Optical Upper Limits
  53. GRB 220701A: Swift/UVOT Upper Limits
  54. GRB 220701A: Lowell Discovery Telescope Optical Observations
  55. GRB 200701A: KAIT Optical Upper Limit
  56. Fermi-LAT Gamma-ray Observations of IceCube-220629A
  57. GRB 220627A, GROND observations
  58. GRB 220624A: AGILE/GRID refined analysis
  59. GRB 220627A: Swift/UVOT Upper Limits
  60. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  61. IceCube-220629A: No significant detection in HAWC
  62. IceCube-220629A - IceCube observation of a high-energy neutrino candidate track-like event
  63. IceCube-220627A: No significant detection in HAWC
  64. GRB 220627A: Swift-XRT afterglow detection
  65. Konus-Wind detection of GRB 220627A
  66. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  67. GRB 220627A: VLT MUSE redshift
  68. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  69. GRB 220627A: MeerLICHT candidate optical afterglow
  70. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  71. GRB 220627A: Swift/BAT-GUANO detection outside the coded FOV
  72. Konus-Wind detection of GRB 220624A
  73. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  74. GRB 220627A: Swift ToO observations
  75. GRB 220627A: Fermi-LAT detection
  76. GRB 220627A: MeerLICHT detection of two afterglow candidates
  77. Fermi GRB 220627A: Global MASTER-Net observations report
  78. IceCube-Cascade 220625A: Upper limits from a search for additional neutrino events in IceCube
  79. IceCube-220624A: No significant detection in HAWC
  80. GRB 220623A: GIT optical upper limits.
  81. GRB 220624A: CALET Gamma-Ray Burst Monitor detection
  82. GRB 220623A: T193-OHP optical upper limit
  83. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  84. GRB 220624A: Fermi GBM Detection
  85. Fermi GRB 220623B: Global MASTER-Net observations report
  86. Fermi GRB 220624A: Global MASTER-Net observations report
  87. IPN triangulation of GRB 220624A
  88. GRB 220623A: Swift-BAT refined analysis
  89. GRB 220624A: Swift/BAT-GUANO detection outside the coded FOV
  90. GRB 220611A: X-ray afterglow Chandra sub-arcsecond localization
  91. GRB 220624A: AGILE/GRID analysis
  92. GRB 220624A: AGILE detection
  93. Konus-Wind detection of GRB 220623A
  94. GRB 220623A: AbAO optical upper limit
  95. GRB 220623A: Swift-XRT refined Analysis
  96. GRB 220623A: NOT optical observations
  97. GRB 220623A: Swift/UVOT Upper Limits
  98. Konus-Wind detection of GRB 220609B
  99. GRB 220623A: AGILE detection
  100. GRB 220623A: AstroSat CZTI detection

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