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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

3363 results found.

  1. GRB 231215A: radio detection with the VLA
  2. Swift GRB240109.17: Global MASTER-Net observations report
  3. GRB 240107A: AstroSat CZTI detection
  4. GRB 240107A: MAXI/GSC detection
  5. IPN triangulation of GRB 240101C (short)
  6. GRB GRB240101C: Fermi GBM observation
  7. GRB 240101C: Swift/BAT-GUANO detection of a short burst
  8. GRB 240101C: AstroSat CZTI detection
  9. GRB 240101C: GRBAlpha detection
  10. GRB 240101C: Fermi GBM Final Localization
  11. Swift GRB240101.85: Global MASTER-Net observations report
  12. Fermi trigger No 725806648: Global MASTER-Net observations report
  13. Fermi trigger No 725592555: Global MASTER-Net observations report
  14. Fermi trigger No 725143760: Global MASTER-Net observations report
  15. Fermi trigger No 724781422: Global MASTER-Net observations report
  16. GRB 231215A: AMI-LA radio detection
  17. GRB 231214A: Swift-BAT refined analysis
  18. GRB 231216A: BOOTES-2/TELMA optical upper limit
  19. GRB 231205B: VZLUSAT-2 detection
  20. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  21. GRB 231215A: Swift/UVOT Detection
  22. GRB 231210B: MeerLICHT afterglow observations
  23. IceCube Alert 231211.03: Global MASTER-Net observations report
  24. Fermi trigger No 723906955: Global MASTER-Net observations report
  25. IPN triangulation of GRB 231129C
  26. IPN triangulation of GRB 231205A
  27. Fermi trigger No 723581802: Global MASTER-Net observations report
  28. GRB 231129C: ASIM MXGS observation and localization
  29. GRB 231205B: Nanshan/HMT optical upper limit
  30. GRB 231205A: DDOTI Upper Limits on the Afterglow
  31. Fermi trigger No 723326169: Global MASTER-Net observations report
  32. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  33. Fermi trigger No 723412808: Global MASTER-Net observations report
  34. Konus-Wind detection of GRB 231129C
  35. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  36. GRB 231129B: Swift-XRT observations
  37. GRB 231129C: AGILE detection
  38. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  39. GRB 231129A: Swift-BAT refined analysis
  40. GRB 231129C: MASTER OT detection
  41. GRB 231129C: Fermi-LAT detection
  42. GRB 231129C: GRBAlpha detection
  43. GRB 231129C: Glowbug gamma-ray detection
  44. GRB 231129C: GECAM-B detection of a bright burst
  45. GRB 231129C: AstroSat CZTI detection
  46. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  47. GRB 231129C: Fermi GBM Observation of a very bright GRB
  48. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  49. GRB 231129C: MAXI/GSC detection
  50. GRB 231129B: Tiled Swift observations
  51. GRB 231129B: MAXI/GSC detection
  52. Fermi trigger No 722653947: Global MASTER-Net observations report
  53. Fermi trigger No 722400249: Global MASTER-Net observations report
  54. GRB 231117A: GTC Near-Infrared Observations
  55. Konus-Wind detection of GRB 231020A
  56. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  57. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  58. Fermi trigger No 722039659: Global MASTER-Net observations report
  59. GRB 231115A : OHP/T120 optical upper limit
  60. GRB 231117A : MITSuME Akeno optical upper limits
  61. Fermi GRB 231115A: Global MASTER-Net observations report
  62. GRB 231113A (short): Glowbug gamma-ray detection
  63. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  65. Swift GRB231111.60: Global MASTER-Net observations report
  66. Fermi trigger No 721204446: Global MASTER-Net observations report
  67. Fermi GRB 231108A: Global MASTER-Net observations report
  68. Fermi GRB 231106A: Global MASTER-Net observations report
  69. GRB 231104A: NOT upper limit
  70. Fermi GRB 231103A: Global MASTER-Net observations report
  71. Swift GRB231104.07: Global MASTER-Net observations report
  72. GRB 231030B: AstroSat CZTI detection
  73. Fermi GRB 231030B: Global MASTER-Net observations report
  74. Fermi trigger No 720224759: Global MASTER-Net observations report
  75. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  76. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  77. GRB 231020A: AstroSat CZTI detection
  78. Fermi trigger No 719846439: Global MASTER-Net observations report
  79. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  81. GRB 231018A: Fermi GBM Detection
  82. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  83. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  84. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  85. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  86. LIGO/Virgo/KAGRA S230917af: MAXI/GSC observations
  87. Fermi trigger No 716449174: Global MASTER-Net observations report
  88. GRB 230903A: Enhanced Swift-XRT position
  89. GRB 230903A: Swift-BAT refined analysis
  90. Fermi trigger No 715552087: Global MASTER-Net observations report
  91. GRB 230826A: Swift-BAT refined analysis
  92. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  93. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  94. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  95. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  96. Swift GRB230821.64: Global MASTER-Net observations report
  97. GRB 230818A: Tautenburg observations
  98. GRB 230818A: Leavitt Observatory upper limit
  99. GRB 230818A: SAO RAS Zeiss-1000 observations
  100. Fermi GRB 230818A: Global MASTER-Net observations report

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