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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"

3763 results found.

  1. Fermi trigger No 647365516: Global MASTER-Net observations report
  2. Integral GRB210707.02: Global MASTER-Net observations report
  3. Fermi trigger No 647108723: Global MASTER-Net observations report
  4. Fermi trigger No 647120009: Global MASTER-Net observations report
  5. GRB210702A: MeerLICHT multi-colour photometry
  6. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  7. IceCube-210629A: Upper limits from a search for additional neutrino events in IceCube
  8. Fermi trigger No 646443989: Global MASTER-Net observations report
  9. Fermi GRB 210627B: Global MASTER-Net observations report
  10. Fermi GRB 210627A: Global MASTER-Net observations report
  11. GRB 210619B: ASIM observation
  12. Fermi trigger No 646189108: Global MASTER-Net observations report
  13. Fermi trigger No 646194855: Global MASTER-Net observations report
  14. GRB 210619B: Mini-MegaTORTORA early optical observations
  15. GRB 210619B: Ondrejov D50 detection
  16. GRB 210618A: DDOTI upper limit for the optical afterglow
  17. Swift GRB210618.07: Global MASTER-Net observations report
  18. Fermi GRB 210615A: Global MASTER-Net observations report
  19. GRB 210610B: Further SAO RAS optical observations
  20. GRB 201228B: Fermi GBM observation
  21. GRB 210610B: SAO RAS optical observations
  22. GRB 210610A: Swift-BAT refined analysis
  23. Fermi trigger No 645047470: Global MASTER-Net observations report
  24. GRB 210610A: Xinglong-2.16m optical afterglow observations
  25. GRB 210610A: Swift detection of a burst with an optical counterpart
  26. GRB 210607A/MAXI J1733-222: MAXI/GSC detection
  27. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  28. Fermi trigger No 644359567: Global MASTER-Net observations report
  29. Fermi GRB 210601A: Global MASTER-Net observations report
  30. Fermi GRB 210529A: Global MASTER-Net observations report
  31. Fermi GRB 210529B: Global MASTER-Net observations report
  32. GRB 210528A: Fermi GBM detection
  33. GRB 210528A: AstroSat CZTI detection
  34. GRB 210528B: MAXI/GSC detection
  35. Fermi GRB 210528A: Global MASTER-Net observations report
  36. GRB 210528A: BALROG localization (Fermi Trigger 643903431 / GRB 210528586)
  37. GRB 210528A: Fermi GBM Final Real-time Localization
  38. GRB 210527A: MITSuME Akeno optical upper limits
  39. Fermi GRB 210518A: Global MASTER-Net observations report
  40. Fermi trigger No 642991619: Global MASTER-Net observations report
  41. GRB 210517A: AGILE detection
  42. GRB 210517A: Swift detection of a burst
  43. Fermi GRB 210515A: Global MASTER-Net observations report
  44. IPN triangulation of GRB 210427A
  45. Fermi GRB 210511A: Global MASTER-Net observations report
  46. Fermi GRB 210510A: Global MASTER-Net observations report
  47. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  48. Fermi GRB 210507A: Global MASTER-Net observations report
  49. GRB 210504A: Swift detection of a burst
  50. Fermi GRB 210501A: Global MASTER-Net observations report
  51. IPN triangulation of GRB 210424B (short/hard)
  52. Fermi trigger No 640695289: Global MASTER-Net observations report
  53. Swift GRB 210421A: Global MASTER-Net observations report
  54. GRB 210421A: Swift detection of a burst
  55. Fermi GRB 210419B: Global MASTER-Net observations report
  56. GRB 210419B: Fermi GBM Final Real-time Localization
  57. Fermi GRB 210411B: Global MASTER-Net observations report
  58. Fermi GRB 210411A: Global MASTER-Net observations report
  59. GRB 210409A: GECAM detection
  60. Konus-Wind detection of GRB 210406A
  61. Integral GRB210406.72: Global MASTER-Net observations report
  62. Fermi trigger No 639199407: Global MASTER-Net observations report
  63. GRB 210328A: AstroSat CZTI detection
  64. Fermi trigger No 639093861: Global MASTER-Net observations report
  65. GRB 210328A: GECAM detection
  66. GRB 210328A: BALROG localization (Fermi Trigger / GRB 210328865)
  67. GRB 210328A: Fermi GBM Final Real-time Localization
  68. Fermi GRB 210324B: Global MASTER-Net observations report
  69. GRB 210324A: Fermi GBM Final Real-time Localization
  70. IceCube Alert 210322.11: Global MASTER-Net observations report
  71. GRB 210321A: Redshift from OSIRIS/GTC
  72. GRB 210320A: MAXI/GSC detection
  73. Fermi trigger No 637729731: Global MASTER-Net observations report
  74. Fermi trigger No 637521056: Global MASTER-Net observations report
  75. Fermi GRB 210312A: Global MASTER-Net observations report
  76. GRB 171205A: Continued ATCA observations
  77. Fermi trigger No 637027080: Global MASTER-Net observations report
  78. GRB 210308A: Swift/UVOT Detection
  79. GRB 210308A: Swift detection of a burst with an optical counterpart
  80. GRB 210307A: LCO Optical Upper Limits
  81. Fermi trigger No 636459103: Global MASTER-Net observations report
  82. Fermi trigger No 636187116: Global MASTER-Net observations report
  83. Fermi trigger No 636168178: Global MASTER-Net observations report
  84. GRB 210217A: Liverpool Telescope First Hour Observations
  85. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued CrAO and AbAO optical observations
  86. Fermi GRB 210207A: Global MASTER-Net observations report
  87. VLT/X-shooter redshift of 1.466 for ZTF21aagwbjr/AT2021buv, strengthening its association with GRB 210204A
  88. Recent activity of SGR 1935+2154 as observed by CGBM
  89. Konus-Wind detection of two bright bursts from SGR 1935+2154
  90. Fermi GRB 210120A: Global MASTER-Net observations report
  91. Konus-Wind detection of GRB 210112A
  92. GRB 201227A: ASIM observation
  93. GW170817: HST observations at 3.4 years from merger
  94. GRB 210104A: early ATLAS detections of the bright afterglow
  95. GRB 210104A: 1.3m DFOT Optical Afterglow Detection
  96. GRB 210104A: MITSuME Akeno optical observation
  97. GRB 210104A: GWAC-F60A optical afterglow observations
  98. GRB 210104A: Swift detection of a burst with a bright optical counterpart
  99. Fermi GRB 210102C: Global MASTER-Net observations report
  100. MAXI GRB210102.38: Global MASTER-Net observations report

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