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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"

21112 results found.

  1. GRB 220310A: MASTER optical counterpart detection
  2. GRB 220310A: Swift ToO observations
  3. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  4. Fermi GRB 220310B: Global MASTER-Net observations report
  5. MAXI GRB220310.02: Global MASTER-Net observations report
  6. ZTF22aabjpxh/AT2022cva: AMI-LA radio observation
  7. Fermi GRB 220309A: Global MASTER-Net observations report
  8. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  9. Fermi trigger No 668410535: Global MASTER-Net observations report
  10. GRB 220306B: Tautenburg observations
  11. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  12. GRB 220306B: AbAO optical observations, possible afterglow candidate
  13. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  14. Swift GRB 220306B: Global MASTER-Net observations report
  15. Fermi GRB 220306A: Global MASTER-Net observations report
  16. Fermi GRB 220305A: Global MASTER-Net observations report
  17. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  18. Swift GRB 220305A: Global MASTER-Net observations report
  19. GRB 220305A: Swift-XRT observations
  20. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  21. GRB 220302A: Swift/UVOT Upper Limits
  22. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  23. IceCube Alert 220304.74: Global MASTER-Net observations report
  24. Fermi GRB 220304A: Global MASTER-Net observations report
  25. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  26. IceCube Alert 220303.75: Global MASTER-Net observations report
  27. Swift resumes autonomous slewing
  28. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  29. ZTF22aaajecp/AT2022cmc: ATCA detection
  30. Swift GRB 220302A: Global MASTER-Net observations report
  31. GRB 220302A: Swift detection of a burst
  32. Fermi trigger No 667737010: Global MASTER-Net observations report
  33. ZTF22aaajecp/AT2022cmc: JCMT SCUBA-2 sub-mm observations
  34. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  35. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  36. IceCube Alert 220225.59: Global MASTER-Net observations report
  37. ZTF22aaajecp/AT2022cmc: DECam Photometry
  38. GRB 220219B: Swift-XRT observations
  39. ZTF22aabjpxh/AT2022cva (GRB 220219B): Mondy optical observations
  40. Fermi GRB 220223A: Global MASTER-Net observations report
  41. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  42. Fermi GRB 220222B: Global MASTER-Net observations report
  43. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  44. GRB 220219B: Swift ToO observations
  45. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  46. Fermi GRB 220222A: Global MASTER-Net observations report
  47. ZTF22aabjpxh/AT2022cva: Assy optical observations
  48. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  49. ZTF22aaajecb/AT 2022cmc: CAHA 2.2m/CAFOS detection, luminous transient
  50. ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
  51. IceCube Alert 220221.03: Global MASTER-Net observations report
  52. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  53. ZTF22aabjpxh/AT2022cva: ZTF Discovery of a Rapidly Fading Transient with a Likely Long-GRB Counterpart
  54. IceCube Alert 220220.60: Global MASTER-Net observations report
  55. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220220A
  56. Fermi trigger No 666962499: Global MASTER-Net observations report
  57. GRB 220218A: Swift detection of a burst
  58. Swift GRB220218.94: Global MASTER-Net observations report
  59. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  60. Swift resumes pointed science observations
  61. ZTF22aaajecp/AT2022cmc: NICER X-ray detection
  62. GRB 220211A: MASTER optical observations of ZTF22aaajecp/AT2022cmc
  63. ZTF22aaajecp: GIT optical follow-up observations
  64. GRB 211023A: evidence of supernova in LBT spectra
  65. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  66. ZTF22aaajecp/AT2022cmc: VLA radio detection
  67. ZTF22aaajecp/AT2022cmc: Zwicky Transient Facility discovery of a fast and red optical transient
  68. Fermi trigger No 666489765: Global MASTER-Net observations report
  69. GRB 220210A: Mondy, AbAO and Terskol optical upper limits
  70. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220212A
  71. Fermi GRB 220211B: Global MASTER-Net observations report
  72. GRB 220210A: BOOTES-5/JGT optical afterglow candidate discarded
  73. GRB 220210A: BOOTES-5/JGT optical afterglow candidate
  74. Fermi GRB 220211A: Global MASTER-Net observations report
  75. Fermi GRB 220210A: Global MASTER-Net observations report
  76. GRB 210919A: Maidanak optical observations
  77. Fermi GRB 220209A: Global MASTER-Net observations report
  78. Fermi-LAT Gamma-ray Observations of IceCube-220205B
  79. Fermi-LAT Gamma-ray Observations of IceCube-220205A
  80. Fermi-LAT Gamma-ray Observations of IceCube-220202A
  81. IceCube Alert 220202.49: Global MASTER-Net observations report
  82. Fermi GRB 220131A: Global MASTER-Net observations report
  83. Fermi GRB 220129A: Global MASTER-Net observations report
  84. GECAM observations of a series of bursts from SGR J1935+2154
  85. Fermi trigger No 664738369: Global MASTER-Net observations report
  86. GRB 220117A, GROND observations
  87. AGILE observations of a bright burst from SGR 1935+2154
  88. GRB 220118A: 2.2m CAHA/CAFOS detections
  89. GRB 220118A: COATLI Optical Observations
  90. GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  91. Swift currently in safe hold with science slews disabled
  92. GRB 220118A: Swift/UVOT Detection
  93. GRB 220118A: GIT optical observations
  94. Swift GRB220118.50: Global MASTER-Net observations report
  95. Swift GRB 220118A: Global MASTER-Net observations report
  96. GRB 220117B: Swift/UVOT Upper Limits
  97. GRB 220117A: Swift/UVOT Upper Limits
  98. GRB 220117A: LCO Optical Observations
  99. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  100. Fermi-LAT Gamma-ray Observations of IceCube-220115A and detection of a new gamma-ray source, Fermi J2350.2+2620

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