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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"

22207 results found.

  1. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  2. Fermi trigger No 724698747: Global MASTER-Net observations report
  3. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  4. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  5. GRB 231215A: AMI-LA radio detection
  6. GRB 231216A: Nanshan/HMT optical upper limit
  7. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  8. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  9. GRB 231216A: REM NIR upper limits
  10. GRB 231216A: Swift/UVOT Upper Limits
  11. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  12. GRB 231216A: GIT optical upper limit
  13. GRB 231216A: NOT optical upper limits
  14. Swift GRB231216.77: Global MASTER-Net observations report
  15. Konus-Wind detection of GRB 231215A
  16. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  17. GRB 231215A: NOT optical observations
  18. GRB 231214A: Swift/UVOT Upper Limits
  19. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  20. GRB 231215A : OHP/T193 optical afterglow detection
  21. GRB 231215A: Swift/UVOT Detection
  22. ATCA observations of GRB 231210B
  23. Fermi trigger No 724326442: Global MASTER-Net observations report
  24. GRB 231214A: REM optical/NIR upper limits
  25. GRB 231215A: GROWTH-India optical follow-up
  26. GRB 231215A : Nanshan/HMT optical observations
  27. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  28. GRB 231215C: MASTER OT detection
  29. Swift GRB231215.41: Global MASTER-Net observations report
  30. GRB 231215A: Swift-XRT observations
  31. GRB 231214B: Swift/BAT-GUANO detection of a burst
  32. Fermi trigger No 724278269: Global MASTER-Net observations report
  33. Fermi trigger No 724233240: Global MASTER-Net observations report
  34. Swift GRB231214.85: Global MASTER-Net observations report
  35. GRB 231210B: REM optical/NIR upper limits
  36. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
  37. LIGO/Virgo/KAGRA S231206cc: Upper limits from Swift/BAT-GUANO
  38. LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
  39. Fermi trigger No 724035412: Global MASTER-Net observations report
  40. GRB 231210B: MeerLICHT afterglow observations
  41. IceCube Alert 231211.03: Global MASTER-Net observations report
  42. IceCube-231202A: No candidates from the Zwicky Transient Facility
  43. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  44. Fermi trigger No 723906955: Global MASTER-Net observations report
  45. Swift GRB231210.90: Global MASTER-Net observations report
  46. GRB231205B: Swift/UVOT Upper Limits
  47. GRB 231205B: Swift-BAT refined analysis
  48. GRB 231205B: 1.3m DFOT Optical upper limit
  49. GRB 231205B: optical upper limit in TSHAOand AbAO
  50. Fermi trigger No 723581802: Global MASTER-Net observations report
  51. Fermi-LAT gamma-ray observations of IceCube-231202A
  52. GRB 231205B: REM optical/NIR upper limits
  53. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  54. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  55. GRB 231205B: Zadko observatory - Gingin optical observations
  56. GRB 231205B: Gaoyazi/GOT optical upper limit
  57. GRB 231205B: Nanshan/HMT optical upper limit
  58. Swift GRB231205.70: Global MASTER-Net observations report
  59. Fermi trigger No 723435916: Global MASTER-Net observations report
  60. Fermi trigger No 723326169: Global MASTER-Net observations report
  61. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  62. Fermi trigger No 723412808: Global MASTER-Net observations report
  63. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  64. Konus-Wind detection of GRB 231129C
  65. Fermi trigger No 723279695: Global MASTER-Net observations report
  66. GRB 231129C: Swift-XRT afterglow detection
  67. Fermi trigger No 723149952: Global MASTER-Net observations report
  68. GRB 231129B: Swift-XRT observations
  69. Optical transient in the field of Messier 31, likely a new blazar: back to bright state
  70. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  71. GRB 231129A: JinShan optical upper limit
  72. GRB 231129C: Swift-XRT observations
  73. GRB 231129A: Swift/UVOT Upper Limits
  74. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  75. GRB 231129C: Tiled Swift observations
  76. Fermi trigger No 722977823: Global MASTER-Net observations report
  77. GRB 231129B: Tiled Swift observations
  78. Fermi-LAT gamma-ray observations of IceCube-231125A
  79. Integral GRB231129.21: Global MASTER-Net observations report
  80. GRB 231117A: MeerKAT 1.3GHz detection
  81. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  82. Fermi trigger No 722653947: Global MASTER-Net observations report
  83. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  84. Fermi trigger No 722460326: Global MASTER-Net observations report
  85. Fermi trigger No 722507896: Global MASTER-Net observations report
  86. GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
  87. Fermi trigger No 722462310: Global MASTER-Net observations report
  88. GRB 231115A: XMM-Newton observation
  89. GRB 231117A: Mondy optical observations
  90. Fermi trigger No 722400249: Global MASTER-Net observations report
  91. GRB 231118A: REM optical afterglow detection
  92. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  93. GRB 231117A: Chandra afterglow detection
  94. GRB 231117A: Continued GTC Observations
  95. Fermi trigger No 722349867: Global MASTER-Net observations report
  96. GRB 231118A: ATCA detection of radio counterpart
  97. GRB 231117A: Swift/UVOT late time observations
  98. GRB 231117A: GTC Near-Infrared Observations
  99. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  100. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO

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