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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"

21983 results found.

  1. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  2. GRB 231215A: AMI-LA radio detection
  3. GRB 231216A: Nanshan/HMT optical upper limit
  4. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  5. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  6. GRB 231216A: REM NIR upper limits
  7. GRB 231216A: Swift/UVOT Upper Limits
  8. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  9. GRB 231216A: GIT optical upper limit
  10. GRB 231216A: NOT optical upper limits
  11. Swift GRB231216.77: Global MASTER-Net observations report
  12. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  13. GRB 231215A: NOT optical observations
  14. GRB 231214A: Swift/UVOT Upper Limits
  15. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  16. GRB 231215A : OHP/T193 optical afterglow detection
  17. GRB 231215A: Swift/UVOT Detection
  18. ATCA observations of GRB 231210B
  19. Fermi trigger No 724326442: Global MASTER-Net observations report
  20. GRB 231214A: REM optical/NIR upper limits
  21. GRB 231215A : Nanshan/HMT optical observations
  22. GRB 231215C: MASTER OT detection
  23. Swift GRB231215.41: Global MASTER-Net observations report
  24. GRB 231215A: Swift-XRT observations
  25. GRB 231214B: Swift/BAT-GUANO detection of a burst
  26. Fermi trigger No 724278269: Global MASTER-Net observations report
  27. Fermi trigger No 724233240: Global MASTER-Net observations report
  28. Swift GRB231214.85: Global MASTER-Net observations report
  29. GRB 231210B: REM optical/NIR upper limits
  30. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
  31. LIGO/Virgo/KAGRA S231206cc: Upper limits from Swift/BAT-GUANO
  32. LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
  33. Fermi trigger No 724035412: Global MASTER-Net observations report
  34. GRB 231210B: MeerLICHT afterglow observations
  35. IceCube Alert 231211.03: Global MASTER-Net observations report
  36. IceCube-231202A: No candidates from the Zwicky Transient Facility
  37. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  38. Fermi trigger No 723906955: Global MASTER-Net observations report
  39. Swift GRB231210.90: Global MASTER-Net observations report
  40. GRB231205B: Swift/UVOT Upper Limits
  41. GRB 231205B: 1.3m DFOT Optical upper limit
  42. GRB 231205B: optical upper limit in TSHAOand AbAO
  43. Fermi trigger No 723581802: Global MASTER-Net observations report
  44. Fermi-LAT gamma-ray observations of IceCube-231202A
  45. GRB 231205B: REM optical/NIR upper limits
  46. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  47. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  48. GRB 231205B: Zadko observatory - Gingin optical observations
  49. GRB 231205B: Gaoyazi/GOT optical upper limit
  50. GRB 231205B: Nanshan/HMT optical upper limit
  51. Swift GRB231205.70: Global MASTER-Net observations report
  52. Fermi trigger No 723435916: Global MASTER-Net observations report
  53. Fermi trigger No 723326169: Global MASTER-Net observations report
  54. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  55. Fermi trigger No 723412808: Global MASTER-Net observations report
  56. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  57. Fermi trigger No 723279695: Global MASTER-Net observations report
  58. GRB 231129C: Swift-XRT afterglow detection
  59. Fermi trigger No 723149952: Global MASTER-Net observations report
  60. GRB 231129B: Swift-XRT observations
  61. Optical transient in the field of Messier 31, likely a new blazar: back to bright state
  62. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  63. GRB 231129A: JinShan optical upper limit
  64. GRB 231129C: Swift-XRT observations
  65. GRB 231129A: Swift/UVOT Upper Limits
  66. GRB 231129C: Tiled Swift observations
  67. Fermi trigger No 722977823: Global MASTER-Net observations report
  68. GRB 231129B: Tiled Swift observations
  69. Fermi-LAT gamma-ray observations of IceCube-231125A
  70. Integral GRB231129.21: Global MASTER-Net observations report
  71. GRB 231117A: MeerKAT 1.3GHz detection
  72. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  73. Fermi trigger No 722653947: Global MASTER-Net observations report
  74. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  75. Fermi trigger No 722460326: Global MASTER-Net observations report
  76. Fermi trigger No 722507896: Global MASTER-Net observations report
  77. GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
  78. Fermi trigger No 722462310: Global MASTER-Net observations report
  79. GRB 231115A: XMM-Newton observation
  80. GRB 231117A: Mondy optical observations
  81. Fermi trigger No 722400249: Global MASTER-Net observations report
  82. GRB 231118A: REM optical afterglow detection
  83. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  84. GRB 231117A: Chandra afterglow detection
  85. GRB 231117A: Continued GTC Observations
  86. Fermi trigger No 722349867: Global MASTER-Net observations report
  87. GRB 231118A: ATCA detection of radio counterpart
  88. GRB 231117A: Swift/UVOT late time observations
  89. GRB 231117A: GTC Near-Infrared Observations
  90. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  91. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  92. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  93. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  94. GRB 231117A: AMI-LA radio observations
  95. GRB 231117A: LDT Confirmation of Optical Fading
  96. GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
  97. 231118A: Swift-UVOT Detection
  98. GRB231117A: Swift-UVOT detection
  99. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  100. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations

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