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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"

28188 results found.

  1. EP261006a: LT and NOT discovery of an optical counterpart
  2. GRB 261007A: Fermi GBM observation
  3. EP261007a/GRB 261007A: Einstein Probe detection of an X-ray transient
  4. EP261006a: SVOM/VT optical upper limits
  5. EP261006a: Einstein Probe detection of an X-ray transient
  6. GRB 261007A: KAIT optical counterpart candidate
  7. EP trigger 01709320985: SVOM/C-GFT optical upper limits
  8. GRB 261005B: Swift-XRT refined Analysis
  9. EP trigger 01709320985: Ondrejov D50 optical upper limits
  10. GRB 261005A: Glowbug gamma-ray detection
  11. GRB 261005B: Swift/UVOT Upper Limits
  12. GRB 261005B: J-band upper limit with WINTER
  13. GRB 261001A: GECAM-B observation of a likely long GRB
  14. GRB 261005B: Fermi GBM Observation
  15. GRB 261005B: Enhanced Swift-XRT position
  16. GRB 261005B: Swift detection of a burst
  17. GRB 261003A: Glowbug gamma-ray detection of a likely short burst
  18. EP#01709320865: Swift-XRT observations
  19. GRB 260930B: SVOM/GRM observation
  20. Konus-Wind detection of GRB 260919A / EP 260920a
  21. EP261003a: J-band upper limit with WINTER
  22. EP261003a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  23. GRB 260930B: GECAM-B detection of a burst
  24. EP261003a: COLIBRÍ optical upper limits
  25. Fermi GRB 261003A: Global MASTER-Net observations report
  26. EP261003a: Einstein Probe detection of an X-ray transient
  27. EP Alert 261003.01: Global MASTER-Net observations report
  28. Fermi-LAT Gamma-ray Observations of IceCube-260930A
  29. Fermi GBM Detection of GRB 260919A / EP260920a
  30. IceCube-260930A: Upper limits from a search for additional neutrino events in IceCube
  31. Fermi GRB 260930B: Global MASTER-Net observations report
  32. GRB 260926C: SVOM/GRM observation
  33. IceCube Alert 260930A: Global MASTER-Net observations report
  34. EP260927a: SVOM/ECLAIRs Upper Limit
  35. EP260927a: Global MASTER-Net observations report
  36. GRB 260926B: Glowbug gamma-ray detection of a likely short burst
  37. GRB 260926A: Glowbug gamma-ray detection
  38. GRB 260924A: AbAO optical observations
  39. Fermi GRB 260928A: Global MASTER-Net observations report
  40. EP260924a: Global MASTER-Net observations report
  41. GRB 260925A: Swift-BAT refined analysis
  42. GRB 260924A: Upper limits from a neutrino search with IceCube
  43. Fermi GRB 260926C: Global MASTER-Net observations report
  44. GRB260914A: MAO/AZT-22 optical observations
  45. Fermi GRB 260926A: Global MASTER-Net observations report
  46. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  47. GRB 260924A: COLIBRÍ optical observations
  48. EP260924a: J-band upper limit by SYSU 80cm infrared telescope
  49. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  50. GRB 260925A: Swift-XRT refined Analysis
  51. Swift Trigger 1513439 is probably not a GRB
  52. GRB 260925A: Swift/UVOT Upper Limits
  53. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  54. GRB 260923A: Glowbug gamma-ray detection
  55. GRB 260924A: Optical follow-up observations with Kinder
  56. GRB 260922A: Glowbug gamma-ray detection
  57. GRB 260925A: Enhanced Swift-XRT position
  58. GRB 260925A: COLIBRÍ optical upper limits
  59. GRB 260925A: FRAM-Auger optical limit
  60. GRB 260924A: Ondrejov D50 optical afterglow detection
  61. EP260924a: J-band upper limit with WINTER
  62. GRB 260924A: SVOM/GRM observation
  63. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  64. GRB 260925A: Swift detection of a burst
  65. GRB 260923A: Insight-HXMT/HE detection
  66. EP260924a: EP-WXT detection of an X-ray transient
  67. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  68. GRB 260924A: Swift/UVOT Detection
  69. GRB 260924A: GROWTH-India Telescope optical observations
  70. GRB 260924A: Swift-BAT refined analysis
  71. GRB 260924A: NuSTAR detection of prompt emission
  72. GRB 260924A: Swift-XRT refined Analysis
  73. GRB 260922A: NuSTAR detection of prompt emission
  74. GRB 260921A: NuSTAR detection of prompt emission
  75. GRB 260921A: SVOM/GRM observation
  76. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  77. GRB 260924A: Fermi GRB Observation
  78. GRB 260924A: AstroSat CZTI detection
  79. GRB 260920A: SVOM/GRM observation
  80. GRB 260924A: NOT optical counterpart confirmation
  81. GRB 260924A: Enhanced Swift-XRT position
  82. GRB 260924A: Swift detection of a burst
  83. Fermi GRB 260923A: Global MASTER-Net observations report
  84. EP260806a: e-MERLIN detection at 5 GHz
  85. GRB 260922A: Ondrejov D50 optical limit
  86. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  87. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  88. GRB 260922A: Swift-BAT refined analysis
  89. EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
  90. GRB 260922A: J-band upper limit with WINTER
  91. GRB 260922A: Swift/UVOT Upper Limits
  92. GRB 260922A: COLIBRÍ Optical Counterpart Candidate (correction to GCN 45698)
  93. GRB 260922A: COLIBRÍ optical upper limits
  94. GRB 260922A: Swift-XRT refined Analysis
  95. GRB 260922A: Enhanced Swift-XRT position
  96. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  97. GRB 260920A: Glowbug gamma-ray detection
  98. GRB 260922A: SVOM/C-GFT optical upper limit
  99. GRB 260922A: Swift detection of a burst
  100. GRB 260921A: AstroSat CZTI detection

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