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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"

21120 results found.

  1. GRB 220310C: Swift-XRT observations
  2. GRB 220310C: Swift ToO observations
  3. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  4. Integral GRB220311.69: Global MASTER-Net observations report
  5. Integral GRB220311.69: Global MASTER-Net observations report
  6. ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
  7. GRB 220310A: GIT confirmation of optical afterglow.
  8. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  9. GRB 220310A: MASTER optical counterpart detection
  10. GRB 220310A: Swift ToO observations
  11. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  12. Fermi GRB 220310B: Global MASTER-Net observations report
  13. MAXI GRB220310.02: Global MASTER-Net observations report
  14. ZTF22aabjpxh/AT2022cva: AMI-LA radio observation
  15. Fermi GRB 220309A: Global MASTER-Net observations report
  16. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  17. Fermi trigger No 668410535: Global MASTER-Net observations report
  18. GRB 220306B: Tautenburg observations
  19. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  20. GRB 220306B: AbAO optical observations, possible afterglow candidate
  21. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  22. Swift GRB 220306B: Global MASTER-Net observations report
  23. Fermi GRB 220306A: Global MASTER-Net observations report
  24. Fermi GRB 220305A: Global MASTER-Net observations report
  25. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  26. Swift GRB 220305A: Global MASTER-Net observations report
  27. GRB 220305A: Swift-XRT observations
  28. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  29. GRB 220302A: Swift/UVOT Upper Limits
  30. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  31. IceCube Alert 220304.74: Global MASTER-Net observations report
  32. Fermi GRB 220304A: Global MASTER-Net observations report
  33. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  34. IceCube Alert 220303.75: Global MASTER-Net observations report
  35. Swift resumes autonomous slewing
  36. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  37. ZTF22aaajecp/AT2022cmc: ATCA detection
  38. Swift GRB 220302A: Global MASTER-Net observations report
  39. GRB 220302A: Swift detection of a burst
  40. Fermi trigger No 667737010: Global MASTER-Net observations report
  41. ZTF22aaajecp/AT2022cmc: JCMT SCUBA-2 sub-mm observations
  42. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  43. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  44. IceCube Alert 220225.59: Global MASTER-Net observations report
  45. ZTF22aaajecp/AT2022cmc: DECam Photometry
  46. GRB 220219B: Swift-XRT observations
  47. ZTF22aabjpxh/AT2022cva (GRB 220219B): Mondy optical observations
  48. Fermi GRB 220223A: Global MASTER-Net observations report
  49. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  50. Fermi GRB 220222B: Global MASTER-Net observations report
  51. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  52. GRB 220219B: Swift ToO observations
  53. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  54. Fermi GRB 220222A: Global MASTER-Net observations report
  55. ZTF22aabjpxh/AT2022cva: Assy optical observations
  56. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  57. ZTF22aaajecb/AT 2022cmc: CAHA 2.2m/CAFOS detection, luminous transient
  58. ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
  59. IceCube Alert 220221.03: Global MASTER-Net observations report
  60. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  61. ZTF22aabjpxh/AT2022cva: ZTF Discovery of a Rapidly Fading Transient with a Likely Long-GRB Counterpart
  62. IceCube Alert 220220.60: Global MASTER-Net observations report
  63. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220220A
  64. Fermi trigger No 666962499: Global MASTER-Net observations report
  65. GRB 220218A: Swift detection of a burst
  66. Swift GRB220218.94: Global MASTER-Net observations report
  67. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  68. Swift resumes pointed science observations
  69. ZTF22aaajecp/AT2022cmc: NICER X-ray detection
  70. GRB 220211A: MASTER optical observations of ZTF22aaajecp/AT2022cmc
  71. ZTF22aaajecp: GIT optical follow-up observations
  72. GRB 211023A: evidence of supernova in LBT spectra
  73. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  74. ZTF22aaajecp/AT2022cmc: VLA radio detection
  75. ZTF22aaajecp/AT2022cmc: Zwicky Transient Facility discovery of a fast and red optical transient
  76. Fermi trigger No 666489765: Global MASTER-Net observations report
  77. GRB 220210A: Mondy, AbAO and Terskol optical upper limits
  78. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220212A
  79. Fermi GRB 220211B: Global MASTER-Net observations report
  80. GRB 220210A: BOOTES-5/JGT optical afterglow candidate discarded
  81. GRB 220210A: BOOTES-5/JGT optical afterglow candidate
  82. Fermi GRB 220211A: Global MASTER-Net observations report
  83. Fermi GRB 220210A: Global MASTER-Net observations report
  84. GRB 210919A: Maidanak optical observations
  85. Fermi GRB 220209A: Global MASTER-Net observations report
  86. Fermi-LAT Gamma-ray Observations of IceCube-220205B
  87. Fermi-LAT Gamma-ray Observations of IceCube-220205A
  88. Fermi-LAT Gamma-ray Observations of IceCube-220202A
  89. IceCube Alert 220202.49: Global MASTER-Net observations report
  90. Fermi GRB 220131A: Global MASTER-Net observations report
  91. Fermi GRB 220129A: Global MASTER-Net observations report
  92. GECAM observations of a series of bursts from SGR J1935+2154
  93. Fermi trigger No 664738369: Global MASTER-Net observations report
  94. GRB 220117A, GROND observations
  95. AGILE observations of a bright burst from SGR 1935+2154
  96. GRB 220118A: 2.2m CAHA/CAFOS detections
  97. GRB 220118A: COATLI Optical Observations
  98. GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  99. Swift currently in safe hold with science slews disabled
  100. GRB 220118A: Swift/UVOT Detection

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