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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"

5401 results found.

  1. IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube
  2. Fermi GRB 221221A: Global MASTER-Net observations report
  3. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  4. Fermi trigger No 692713692: Global MASTER-Net observations report
  5. Swift Trigger 1144538 is not a GRB
  6. Fermi GRB 221211A: Global MASTER-Net observations report
  7. GRB 221208A: AstroSat CZTI detection
  8. GRB 221209B: Fermi GBM Final Real-time Localization
  9. GRB 221203C: AstroSat CZTI detection
  10. GRB 221202B: Detection by VZLUSAT-2
  11. GRB 221202A: MeerLICHT upper limits
  12. IceCube Alert 221124.66: Global MASTER-Net observations report
  13. GRB 221115A: Fermi GBM detection
  14. GRB 221110A: COATLI Second-Epoch Upper Limits
  15. GRB 221110A: COATLI Afterglow detection
  16. GRB 221110A: LCOGT Optical Afterglow Detection
  17. IceCube-221104A: Upper limits from a search for additional neutrino events in IceCube
  18. GRB 221028A: COATLI Upper Limits
  19. GRB 221028A: Swift detection of a burst
  20. GRB 221024A: Mondy optical observations
  21. IPN triangulation of GRB 221022C (short)
  22. LAT GRB221025.04: Global MASTER-Net observations report
  23. GRB221009A: LBT optical imaging
  24. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  25. GRB 221017A: MAXI/GSC detection
  26. GRB 221009A: Armchair Energetics
  27. GRB 221009A: Lowell Discovery Telescope Afterglow Detection
  28. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  29. Fermi trigger No 687345829: Global MASTER-Net observations report
  30. Fermi trigger No 687344475: Global MASTER-Net observations report
  31. Fermi trigger No 687340841: Global MASTER-Net observations report
  32. Fermi trigger No 687337536: Global MASTER-Net observations report
  33. Fermi trigger No 687281393: Global MASTER-Net observations report
  34. GRB 221009A/Swift J1913.1+1946: SMA observations
  35. GRB 221009A: NuSTAR Detection
  36. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  37. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  38. GRB 221009A: Fermi-LAT refined analysis
  39. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  40. Fermi trigger No 687014224: Global MASTER-Net observations report
  41. Fermi trigger No 686403226: Global MASTER-Net observations report
  42. Fermi trigger No 686350260: Global MASTER-Net observations report
  43. Ultra-long GRB 220525B: Konus-Wind and Fermi-GBM detection
  44. Fermi GRB 220925A: Global MASTER-Net observations report
  45. Fermi trigger No 685748699: Global MASTER-Net observations report
  46. Fermi trigger No 684894705: Global MASTER-Net observations report
  47. IceCube-220907A: No significant detection in HAWC
  48. Fermi GRB 220912A: Global MASTER-Net observations report
  49. GRB 220831A: Gemini-South Infrared Observations
  50. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  51. IceCube Alert 220907.28: Global MASTER-Net observations report
  52. Fermi GRB 220902A: Global MASTER-Net observations report
  53. Fermi trigger No 683654200: Global MASTER-Net observations report
  54. GRB 220827A: Fermi GBM Final Real-time Localization
  55. Fermi trigger No 683202084: Global MASTER-Net observations report
  56. Fermi trigger No 683183601: Global MASTER-Net observations report
  57. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  58. GRB 220823A: Fermi GBM detection
  59. Fermi trigger No 682918137: Global MASTER-Net observations report
  60. GRB 220813A: Swift detection of a burst with an optical counterpart
  61. Fermi trigger No 681890304: Global MASTER-Net observations report
  62. Fermi trigger No 681719116: Global MASTER-Net observations report
  63. Fermi trigger No 681633544: Global MASTER-Net observations report
  64. Fermi trigger No 681271717: Global MASTER-Net observations report
  65. GRB 220803A: AstroSat CZTI detection
  66. Fermi trigger No 681212354: Global MASTER-Net observations report
  67. Fermi trigger No 680782656: Global MASTER-Net observations report
  68. Fermi GRB 220728A: Global MASTER-Net observations report
  69. Fermi trigger No 680421061: Global MASTER-Net observations report
  70. GRB 220724A: Fermi GBM Final Real-time Localization
  71. GRB 220714B: UVOT afterglow discovery
  72. Fermi GRB 220711B: Global MASTER-Net observations report
  73. GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
  74. GRB 220701A: COATLI Optical Upper Limit
  75. IceCube-220629A: No significant detection in HAWC
  76. IceCube-220627A: No significant detection in HAWC
  77. IceCube Alert 220627.74: Global MASTER-Net observations report
  78. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  79. Swift GRB220620.02: Global MASTER-Net observations report
  80. Fermi trigger No 677307509: Global MASTER-Net observations report
  81. IPN triangulation of GRB 220606C
  82. Fermi trigger No 676909037: Global MASTER-Net observations report
  83. GRB 220608A: AstroSat CZTI detection
  84. Fermi GRB 220608A: Global MASTER-Net observations report
  85. GRB 220608A: Fermi GBM Final Real-time Localization
  86. GRB 220606B: Fermi GBM Observation
  87. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  88. Fermi GRB 220606B: Global MASTER-Net observations report
  89. GRB 220606B: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 675992935: Global MASTER-Net observations report
  91. Fermi trigger No 675411172: Global MASTER-Net observations report
  92. GRB 220527A: NOT optical photometry and spectroscopic redshift
  93. GRB 220521B: CALET Gamma-Ray Burst Monitor detection
  94. IPN triangulation of GRB 220524A
  95. IPN triangulation of GRB 220522B
  96. Konus-Wind detection of GRB 220521B
  97. IPN triangulation of GRB 220521B
  98. Fermi GRB 220523B: Global MASTER-Net observations report
  99. GRB 220521A: Swift detection of a burst
  100. GRB 220518A: Swift/UVOT Detection

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