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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"

21135 results found.

  1. ZTF20acozryr/AT2020yxz (GRB 201103B): SAO RAS optical observations
  2. ZTF20acozryr/AT2020yxz (GRB 201103B): correction to the GCN #28883 CrAO/ZTSh optical observations
  3. Fermi trigger No 627438255: Global MASTER-Net observations report
  4. Fermi-LAT Gamma-ray Observations of IceCube-201114A
  5. GRB 201116A: NOT optical observations
  6. GRB 201116A: Swift-XRT afterglow detection
  7. GRB 201116A: OSN Afterglow Candidate
  8. IceCube Alert 201115.67: Global MASTER-Net observations report
  9. Fermi trigger No 627198169: Global MASTER-Net observations report
  10. GRB 201116A: Tiled Swift observations
  11. LAT GRB201116.03: Global MASTER-Net observations report
  12. IceCube Alert 201115.09: Global MASTER-Net observations report
  13. Fermi-LAT Gamma-ray Observations of IceCube-201115A
  14. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  15. IceCube-201114A: Upper limits from Fermi GBM Observations
  16. VLASS identifies possible radio counterparts to IceCube-201115A, including a bright BL Lac candidate
  17. Swift-XRT observations of IceCube 201114A
  18. IceCube Alert 201114.63: Global MASTER-Net observations report
  19. ZTF20acozryr/AT2020yxz (GRB 201103B): CrAO/ZTSh optical observations
  20. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  21. ZTF20acozryr/AT2020yxz (GRB 201103B): Mondy continued optical observations
  22. Fermi GRB 201111A: Global MASTER-Net observations report
  23. ZTF20acozryr/AT2020yxz (GRB 201103B): Flattening of the optical light curve
  24. ZTF20acozryr (GRB 201103B): GROWTH-India Telescope optical observations
  25. ZTF20acozryr/AT2020yxz (GRB 201103B): Mondy, Kitab, TSHAO optical observations
  26. GRB 201104B: continued TSHAO optical observation
  27. Fermi GRB 201109A: Global MASTER-Net observations report
  28. Fermi GRB 201108A: Global MASTER-Net observations report
  29. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-201107A
  30. GRB 201103B: GMG observation (2nd epoch)
  31. ZTF20acozryr/AT2020yxz (GRB 201103B): Assy optical observations
  32. GRB 201104B: 1.3m DFOT optical observations
  33. GRB 201104A: Swift-XRT observations
  34. Swift XRT and UVOT detection of ZTF20acozryr/AT2020yxz/GRB201103B
  35. GRB 201015A: Swift-XRT late time observations
  36. GRB 201104B: Kitab optical observations
  37. GRB 201103B (ZTF20acozryr/AT2020yxz): Xinglong-2.16m optical observations
  38. Fermi trigger No 626247072: Global MASTER-Net observations report
  39. GRB 201104B: Swift/UVOT Detection
  40. Correcton to GCN 28848: Swift observes ZTF20acozryr
  41. GRB 201104C: Swift ToO observations
  42. GRB 201103B (ZTF20acozryr/AT2020yxz): Nanshan/NEXT-0.6m optical observations
  43. GRB 201104A: Tiled Swift observations
  44. GRB 201104B: Swift/UVOT Detection
  45. Fermi GRB 201104A: Global MASTER-Net observations report
  46. Fermi GRB 201103A: Global MASTER-Net observations report
  47. Swift GRB 201031A: Global MASTER-Net observations report
  48. Fermi GRB 201031B: Global MASTER-Net observations report
  49. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  50. Swift GRB 201029A: Global MASTER-Net observations report
  51. GRB 201029A: Swift/UVOT Upper Limits
  52. Fermi trigger No 625695596: Global MASTER-Net observations report
  53. GRB 201027A: Swift/UVOT Upper Limits
  54. Baksan Neutrino Observatory Alert 201027.41: Global MASTER-Net observations report
  55. GRB 201026A: Swift/UVOT Upper Limits
  56. Swift GRB201027.05: Global MASTER-Net observations report
  57. GRB 201026A: NanShan/NEXT-0.6m optical upper limit
  58. GRB 201026A: NOT optical upper limits
  59. Swift GRB201026.94: Global MASTER-Net observations report
  60. GRB 201024A: 1.3m DFOT optical observations
  61. GRB 201020B: 1.3m DFOT continued optical follow-up observations
  62. GRB201024A: rebrightening after initial steep decline
  63. GRB 201020B: HCT and GIT continued optical follow-up observations
  64. GRB 201024A: Swift/UVOT Detection
  65. GRB 201020B: follow-up observations with Savelli Telescope
  66. GRB 201020B: 1.3m DFOT optical observations
  67. GRB 201024A: VIRT optical observations
  68. GRB 201020B: follow-up observations at Konkoly
  69. GRB 201020B: continued Mondy optical observations
  70. GRB 201020B: Redshift from GTC/OSIRIS
  71. GRB 201024A: Redshift from GTC/OSIRIS
  72. GRB 201024A: BOOTES-2/TELMA early optical observation and 1.5m OSN follow-up
  73. Swift GRB201024.12: Global MASTER-Net observations report
  74. IceCube-201021A: One candidate counterpart from the Zwicky Transient Facility
  75. GRB 201020B: GROWTH-India Telescope optical observations
  76. Baksan Neutrino Observatory Alert 201022.66: Global MASTER-Net observations report
  77. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  78. Swift-XRT observations of IceCube 201021A (2)
  79. GRB 201021C: Swift/UVOT Detection
  80. GRB 201020B: Swift/UVOT Detection
  81. GRB 201020A: Swift/UVOT Observations
  82. GRB 201014A: 2.0m HCT upper limit
  83. GRB 201020B: Swift-XRT afterglow detection
  84. GRB 201020A: VIRT optical observations
  85. IceCube-201021A: Upper limits from Fermi-GBM Observations
  86. HAWC-201019A: not observable by Fermi-GBM
  87. Swift GRB201021.85: Global MASTER-Net observations report
  88. MAXI GRB201021.68: Global MASTER-Net observations report
  89. GRB200826A: GMOS-N detection of a supernova bump
  90. GRB 201020B: Mondy optical observations
  91. Swift-XRT observations of IceCube 201021A
  92. IceCube Alert 201021.28: Global MASTER-Net observations report
  93. GRB 201015A: SAO RAS optical observations
  94. GRB 201020B: Swift ToO observations
  95. GRB 201020B: Nanshan/NEXT optical afterglow confirmation
  96. GRB 201020A: Redshift from GTC/OSIRIS
  97. GRB 201020B: Fermi-LAT detection
  98. GRB 201020A: DOAO optical afterglow observations
  99. GRB 201020A: GROWTH-India Telescope optical observations
  100. Alert from the HAWC Burst Monitor HAWC-201019A

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