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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"

3119 results found.

  1. GRB 210420B: Tautenburg observations
  2. Fermi GRB 210420A: Global MASTER-Net observations report
  3. Swift GRB 210421A: Global MASTER-Net observations report
  4. GRB 210413B: LOAO optical upper limit
  5. GRB 210411B: AstroSat CZTI detection
  6. Fermi GRB 210411B: Global MASTER-Net observations report
  7. GRB 210406A: 10.4m GTC follow-up observation
  8. GRB 210411B: Fermi GBM Final Real-time Localization
  9. Fermi GRB 210411A: Global MASTER-Net observations report
  10. GRB 210406B: Fermi GBM detection
  11. GRB 210324C: AstroSat CZTI detection
  12. GRB 210320A: MAXI/GSC detection
  13. GRB 210318A: Swift detection of a burst
  14. Fermi trigger No 637521056: Global MASTER-Net observations report
  15. Fermi GRB 210312A: Global MASTER-Net observations report
  16. GRB 210306A: continued Mondy optical observations
  17. Fermi trigger No 636926765: Global MASTER-Net observations report
  18. GRB 210306A: iTelescope T24 optical observations
  19. Trigger 1035744: Swift detection of Sco X-1 due to Star Tracker loss of lock
  20. Fermi trigger No 636459103: Global MASTER-Net observations report
  21. GRB 210217A: 3.6m DOT optical observations
  22. Integral GRB210227.20: Global MASTER-Net observations report
  23. GRB 210226A: Swift-BAT refined analysis
  24. GRB 210217A: Swift detection of a burst with an optical counterpart
  25. IceCube Alert 210213.78: Global MASTER-Net observations report
  26. GRB 210213A: Fermi GBM Final Real-time Localization
  27. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued CrAO and AbAO optical observations
  28. GRB 210211A: Swift/UVOT Detection
  29. Fermi GRB 210210B: Global MASTER-Net observations report
  30. IceCube-210210A: Two Candidate Counterparts from the Zwicky Transient Facility
  31. GRB 210207B: AbAO optical upper limit
  32. GRB 210204A (ZTF21aagwbjr/AT2021buv): Mondy and AbAO optical observations
  33. GRB 210205A: Swift detection of a burst
  34. GRB 210204B: Fermi GBM Final Real-time Localization
  35. GRB 210127A: Fermi GBM Final Real-time Localization
  36. GECAM detection of a burst possibly from the X-ray burster 4U 0614+09 or GRB 210124A
  37. Correction to GCN 29288: NuEm-210111A: No counterpart candidates in INTEGRAL SPI-ACS observation
  38. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-210111A
  39. GRB 210110A: MAXI/GSC detection
  40. Fermi trigger No 631602681: Global MASTER-Net observations report
  41. GRB 210105A: Fermi GBM Final Real-time Localization
  42. Fermi GRB 210102C: Global MASTER-Net observations report
  43. MAXI GRB210102.38: Global MASTER-Net observations report
  44. GRB 201216C: TSHAO, Terskol, Mondy optical upper limits
  45. Fermi GRB 201229B: Global MASTER-Net observations report
  46. Baksan Neutrino Observatory Alert 201228.36: Global MASTER-Net observations report
  47. Fermi GRB 201228B: Global MASTER-Net observations report
  48. Fermi trigger No 630681391: Global MASTER-Net observations report
  49. IceCube-201222A: No Candidate Counterparts from the Zwicky Transient Facility
  50. Baksan Neutrino Observatory Alert 201223.60: Global MASTER-Net observations report
  51. GRB 201221D: LCOGT upper limits
  52. GRB 201221E: Fermi GBM Final Real-time Localization
  53. correction to GCN 29110 - Fermi GBM Sub-Threshold Detection of GRB 201221A
  54. Fermi GBM Sub-Threshold Detection of GRB 201221A
  55. Konus-Wind detection of GRB 201216C
  56. Baksan Neutrino Observatory Alert 201216.94: Global MASTER-Net observations report
  57. GRB 201216C: VLT afterglow candidate discovery
  58. GRB 201015A: optical observations and supernova identification
  59. IceCube-201209A: No Candidate Counterparts from the Zwicky Transient Facility
  60. GRB 201209A: Swift detection of a burst
  61. Fermi GRB 201208A: Global MASTER-Net observations report
  62. IceCube-201130A: No Candidate Counterparts from the Zwicky Transient Facility
  63. IceCube-201130A: No significant detection in HAWC
  64. GRB201130A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 628407054)
  65. Fermi trigger No 628140709: Global MASTER-Net observations report
  66. Fermi GRB 201121A: Global MASTER-Net observations report
  67. Fermi GRB 201120B: Global MASTER-Net observations report
  68. Fermi trigger No 627198169: Global MASTER-Net observations report
  69. GRB 201116A: Fermi-LAT detection
  70. IceCube Alert 201115.09: Global MASTER-Net observations report
  71. GRB 201116A: BALROG localization (Fermi Trigger 627180592 / GRB 201116035)
  72. GRB 201116A: Fermi GBM Final Real-time Localization
  73. IceCube-201114A: No neutrino counterpart candidates in ANTARES search
  74. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  75. Konus-Wind observation of GRB 201103B
  76. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-201107A
  77. Fermi trigger No 626247072: Global MASTER-Net observations report
  78. GRB 201103B (ZTF20acozryr/AT2020yxz): Nanshan/NEXT-0.6m optical observations
  79. IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
  80. GRB 201105B: Fermi GBM observation
  81. ZTF20acozryr/AT2020yxz: Zwicky Transient Facility discovery of a fast optical transient with no associated GRB
  82. GRB 201026A: Swift detection of a burst
  83. GRB 201020B: follow-up observations with Savelli Telescope
  84. GRB 201024A: Redshift from GTC/OSIRIS
  85. IceCube-201021A: No significant detection in HAWC
  86. IceCube-201021A: One candidate counterpart from the Zwicky Transient Facility
  87. Konus-Wind detection of GRB 201020A
  88. IceCube-201021A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  89. GRB 201020A: DOAO optical afterglow observations
  90. GRB 201020A: Fermi GBM observation
  91. GRB 201020A: Swift detection of a burst with an optical counterpart.
  92. GRB 201008A: Swift-XRT afterglow detection
  93. GRB 201016A: Fermi GBM detection
  94. GRB 201013A: TSHAO and AbAO optical observations, afterglow confirmation
  95. GRB 201013A: FRAM-ORM possible afterglow candidate
  96. IceCube-201007A: No candidate counterparts from the Zwicky Transient Facility
  97. GRB 201013A: Swift detection of a burst
  98. GRB 201008A: Swift-XRT observations
  99. Fermi trigger No 623470566: Global MASTER-Net observations report
  100. Fermi trigger No 623493962: Global MASTER-Net observations report

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