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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"

19217 results found.

  1. GRB 261003A: Fermi GBM Final Real-time Localization
  2. EP Alert 261003.01: Global MASTER-Net observations report
  3. Fermi-LAT Gamma-ray Observations of IceCube-260930A
  4. Fermi GBM Detection of GRB 260919A / EP260920a
  5. IceCube-260930A: Upper limits from a search for additional neutrino events in IceCube
  6. Fermi GRB 260930B: Global MASTER-Net observations report
  7. GRB 260926C: SVOM/GRM observation
  8. GRB 260930B: Fermi GBM Final Real-time Localization
  9. GRB 260930A: Fermi GBM Final Real-time Localization
  10. IceCube Alert 260930A: Global MASTER-Net observations report
  11. The EP-WXT trigger 01709320790 is likely a flaring star
  12. EP260927a: SVOM/ECLAIRs Upper Limit
  13. GRB 260926C: AstroSat CZTI detection
  14. GRB 260926C: GECAM-B observation
  15. GRB 260926A: GECAM-B observation
  16. EP260927a: Global MASTER-Net observations report
  17. EP260927a: Einstein Probe detection of a fast X-ray transient
  18. GRB 260926B: Glowbug gamma-ray detection of a likely short burst
  19. GRB 260926A: Glowbug gamma-ray detection
  20. GRB 260924A: VLA detection
  21. GRB 260924A: AbAO optical observations
  22. Fermi GRB 260928A: Global MASTER-Net observations report
  23. GRB 260928A: Fermi GBM Final Real-time Localization
  24. EP260924a: Global MASTER-Net observations report
  25. GRB 260925A: Swift-BAT refined analysis
  26. GRB 260924A: Upper limits from a neutrino search with IceCube
  27. Fermi GRB 260926C: Global MASTER-Net observations report
  28. GRB 260926C: Fermi GBM Final Real-time Localization
  29. GRB260914A: MAO/AZT-22 optical observations
  30. GRB 260926B: Fermi GBM Final Real-time Localization
  31. Fermi GRB 260926A: Global MASTER-Net observations report
  32. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  33. GRB 260926A: Fermi GBM Final Real-time Localization
  34. The EP-WXT trigger 01709320726 is likely a flaring star
  35. GRB 260924A: COLIBRÍ optical observations
  36. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  37. EP260924a: J-band upper limit by SYSU 80cm infrared telescope
  38. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  39. GRB 260925A: Swift-XRT refined Analysis
  40. EP260924a: EP-FXT follow-up observation
  41. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  42. GRB 260923A: Glowbug gamma-ray detection
  43. GRB 260924A: Optical follow-up observations with Kinder
  44. GRB 260922A: Glowbug gamma-ray detection
  45. GRB 260925A: Enhanced Swift-XRT position
  46. GRB 260925A: COLIBRÍ optical upper limits
  47. GRB 260925A: FRAM-Auger optical limit
  48. GRB 260924A: Ondrejov D50 optical afterglow detection
  49. EP260924a: J-band upper limit with WINTER
  50. GRB 260924A: SVOM/GRM observation
  51. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  52. GRB 260925A: Swift detection of a burst
  53. GRB 260923A: Insight-HXMT/HE detection
  54. EP260924a: EP-WXT detection of an X-ray transient
  55. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  56. GRB 260924A: GROWTH-India Telescope optical observations
  57. GRB 260924A: Swift-BAT refined analysis
  58. GRB 260924A: NuSTAR detection of prompt emission
  59. GRB 260924A: Swift-XRT refined Analysis
  60. GRB 260922A: NuSTAR detection of prompt emission
  61. GRB 260921A: NuSTAR detection of prompt emission
  62. GRB 260921A: SVOM/GRM observation
  63. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  64. GRB 260924A: Fermi GRB Observation
  65. GRB 260924A: Fermi-LAT detection of a bright burst
  66. GRB 260924A: AstroSat CZTI detection
  67. GRB 260920A: SVOM/GRM observation
  68. GRB 260924A: NOT optical counterpart confirmation
  69. GRB 260922A: CALET Gamma-Ray Burst Monitor detection
  70. The EP-WXT trigger 01709319842 is likely a flaring star
  71. GRB 260924A: Fermi GBM Final Real-time Localization
  72. Fermi GRB 260923A: Global MASTER-Net observations report
  73. GRB 260923A: Fermi GBM Final Real-time Localization
  74. EP260806a: e-MERLIN detection at 5 GHz
  75. GRB 260922A: Ondrejov D50 optical limit
  76. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  77. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  78. ATCA observations of GRB 260909A
  79. GRB 260922A: Swift-BAT refined analysis
  80. EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
  81. GRB 260922A: J-band upper limit with WINTER
  82. GRB 260922A: COLIBRÍ Optical Counterpart Candidate (correction to GCN 45698)
  83. GRB 260922A: COLIBRÍ optical upper limits
  84. GRB 260922A: Swift-XRT refined Analysis
  85. GRB 260922A: Enhanced Swift-XRT position
  86. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  87. GRB 260920A: Glowbug gamma-ray detection
  88. GRB 260918A: SVOM/ECLAIRs refined analysis
  89. GRB 260922A: SVOM/C-GFT optical upper limit
  90. GRB 260922A: Swift detection of a burst
  91. GRB 260917C: AstroSat CZTI detection
  92. GRB 260920B/EP260920b: GECAM-B detection of a burst
  93. GRB 260921A: AstroSat CZTI detection
  94. GRB 260921A: Swift-BAT refined analysis
  95. GRB 260921B: Fermi GBM Final Localization
  96. GRB 260921A: Fermi GBM Observation
  97. EP260920b: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
  98. EP Alert 260921.58: Global MASTER-Net observations report
  99. GRB 260917B:: SVOM/ECLAIRs refined analysis
  100. The EP-WXT trigger 01709319528 is likely a flaring star

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