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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"
  1. GRB 251016A: HXMT/HE detection
  2. IceCube-251018A: Global MASTER-Net observations report
  3. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  4. GRB 251016A: Swift-XRT afterglow detection
  5. GRB 251017A: Swift/UVOT Detection
  6. GRB 251016A: Swift/UVOT Detection
  7. GRB 251018A: Swift/UVOT Detection
  8. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event
  9. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event (duplicate submission)
  10. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  11. GRB 251016A: VLT/FORS2 Optical Observation
  12. GRB 251017A: COLIBRÍ photometric redshift
  13. GRB 251017A: Swift-XRT refined Analysis
  14. GRB 251018A: MASTER OT detection
  15. GRB 251018A: TRT optical afterglow detection
  16. Swift GRB 251018A: Global MASTER-Net observations report
  17. GRB 251018A: Swift detection of a burst with an optical counterpart
  18. GRB 251018A: Fermi GBM Final Real-time Localization
  19. GRB 251017A: SVOM/VT optical observation
  20. GRB 251011A: Fermi GBM Observation
  21. GRB 251017A: OHP/T193 i-band observations
  22. GRB 251013C: OHP/T193 third epoch optical observations and detected rebrightening
  23. LIGO/Virgo/KAGRA S251017di: Retraction of GW compact binary merger candidate
  24. GRB 251017A: J-band detection with WINTER
  25. GRB 251017A: Glowbug gamma-ray detection
  26. GRB 251013C: Liverpool Telescope observations
  27. GRB 251013C: Leavitt Observatory optical photometry
  28. Fermi GRB 251016B: Global MASTER-Net observations report
  29. GRB 251017A: JinShan observations of the optical afterglow
  30. Swift GRB 251017A: Global MASTER-Net observations report
  31. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  32. Swift Trigger 1404295 is not a GRB
  33. GRB 251016A: AstroSat CZTI detection of a short burst
  34. GRB 251017A: Enhanced Swift-XRT position
  35. GRB 251017A: COLIBRÍ Early Afterglow Detection
  36. GRB 251016B: AstroSat CZTI detection
  37. GRB 251017A: BOOTES-5/JGT early optical afterglow detection
  38. GRB 251017A: Swift detection of a burst with an optical counterpart
  39. GRB 251016A: CALET Gamma-Ray Burst Monitor detection
  40. GRB 251016B: CALET Gamma-Ray Burst Monitor detection
  41. GRB 251013C: JinShan observations of the non-thermal rebrightening of the optical counterpart
  42. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
  43. GRB 251007B: Swift-BAT refined analysis
  44. GRB 251016B: Fermi GBM Final Real-time Localization
  45. GRB 251014D: Swift-BAT refined analysis
  46. GRB 251016A: BOOTES-6/DPRT optical upper limit
  47. GRB 251016A: Glowbug gamma-ray detection of a short burst
  48. GRB 251013C: VLA detection
  49. sb25101602: Swift-XRT counterpart detection
  50. Fermi GRB 251016A: Global MASTER-Net observations report
  51. GRB 251016A: Fermi GBM Final Localization
  52. GRB 251016A: SVOM detection of a short burst
  53. GRB 251014A: Swift-XRT observations
  54. LIGO/Virgo/KAGRA S251014cn: Updated Sky localization
  55. GRB 251014B: PRIME J-band upper limit
  56. Upper limits from a search for additional neutrino events in IceCube
  57. IceCube Alert 251014.77: Global MASTER-Net observations report
  58. Swift GRB251015.60: Global MASTER-Net observations report
  59. GRB 251013C: Kilonova-Catcher optical afterglow detection
  60. Fermi-LAT Gamma-ray Observations of IceCube-251014A
  61. GRB 251013D: Swift/UVOT Observations
  62. GRB 251013C: Swift/UVOT Detection
  63. Konus-Wind detection of GRB 251007A
  64. Fermi Gamma-ray Burst Monitor trigger 782237334/251015673 is not a GRB
  65. GRB 251013C, GCN Circular 42267, errata corrige
  66. GRB 251013C: detection of a radio counterpart at 15.5GHz
  67. GRB 251015A: Fermi GBM Final Real-time Localization
  68. GRB 251013C: SVOM/ECLAIRs refined analysis
  69. GRB 251013D: Swift-XRT observations
  70. Swift Trigger 1404295: possible GRB 251015A
  71. GRB 251014B: Swift-XRT observations
  72. GRB 251014B: Swift/UVOT Upper Limits
  73. GRB 251014B: VLT/FORS2 Optical Observation
  74. GRB 251014D: Swift/UVOT Upper Limits
  75. GRB 251014D: BOOTES-6/DPRT optical upper limit
  76. GRB 251014D: Swift-XRT afterglow detection
  77. GRB 251013C: MAO/AZT-22 optical observations
  78. GRB 251011B: SVOM/VT optical upper limit
  79. GRB 251013C: Swift ToO observations
  80. GRB 251013D: Fermi GBM Observation
  81. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) further multi-band optical observations
  82. GRB 251014A: Swift-BAT refined analysis
  83. IceCube-251014A - IceCube observation of a high-energy neutrino candidate track-like event
  84. GRB 251013C: OHP/T193 further optical observations and possible color evolution
  85. GRB 251013C: Calapai Observatory, Massa S. Giorgio (Messina), optical observation
  86. GRB 251014D: Swift detection of a burst
  87. GRB 251014A: PRIME near-infrared upper limits
  88. GRB 251014C: Fermi GBM Final Localization
  89. GRB 251014A: Glowbug gamma-ray detection of a likely short burst
  90. GRB 251014A: VLT/FORS2 Optical Observation
  91. GRB 251013C: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an bright optical counterpart
  92. GRB 251012A: Glowbug gamma-ray detection of a likely short burst
  93. GRB 251013C: MarSEC, optical afterglow photometry
  94. GRB 251013C: OHP/T193 optical afterglow photometry and spectroscopy
  95. GRB 251014B: Swift ToO observations
  96. GRB 251013D: LAST optical upper limit on Swift/BAT-GUANO localization
  97. GRB 251014B: Swift/BAT-GUANO arcminute localization of a short burst
  98. GRB 251013C: Bassano Bresciano Observatory optical observations
  99. GRB 251013C: Early and late-time optical counterpart detection by LCO
  100. LIGO/Virgo/KAGRA S251014cn: NED Galaxies in the 3-Initial Localization Volume

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