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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"

36232 results found.

  1. GRB 251018A: Fermi GBM Observation
  2. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  3. GRB 251018A: Swift-XRT refined Analysis
  4. GRB 251018A: Enhanced Swift-XRT position
  5. GRB 251016A: HXMT/HE detection
  6. GRB 251016A: Swift-XRT afterglow detection
  7. GRB 251017A: Swift/UVOT Detection
  8. GRB 251016A: Swift/UVOT Detection
  9. GRB 251018A: Swift/UVOT Detection
  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. GRB 251017A: J-band detection with WINTER
  24. GRB 251017A: Glowbug gamma-ray detection
  25. GRB 251013C: Liverpool Telescope observations
  26. GRB 251013C: Leavitt Observatory optical photometry
  27. Fermi GRB 251016B: Global MASTER-Net observations report
  28. GRB 251017A: JinShan observations of the optical afterglow
  29. Swift GRB 251017A: Global MASTER-Net observations report
  30. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  31. Swift Trigger 1404295 is not a GRB
  32. GRB 251016A: AstroSat CZTI detection of a short burst
  33. GRB 251017A: Enhanced Swift-XRT position
  34. GRB 251017A: COLIBRÍ Early Afterglow Detection
  35. GRB 251016B: AstroSat CZTI detection
  36. GRB 251017A: BOOTES-5/JGT early optical afterglow detection
  37. GRB 251017A: Swift detection of a burst with an optical counterpart
  38. GRB 251016A: CALET Gamma-Ray Burst Monitor detection
  39. GRB 251016B: CALET Gamma-Ray Burst Monitor detection
  40. GRB 251013C: JinShan observations of the non-thermal rebrightening of the optical counterpart
  41. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
  42. GRB 251007B: Swift-BAT refined analysis
  43. GRB 251016B: Fermi GBM Final Real-time Localization
  44. GRB 251014D: Swift-BAT refined analysis
  45. GRB 251016A: BOOTES-6/DPRT optical upper limit
  46. GRB 251016A: Glowbug gamma-ray detection of a short burst
  47. GRB 251013C: VLA detection
  48. Fermi GRB 251016A: Global MASTER-Net observations report
  49. GRB 251016A: Fermi GBM Final Localization
  50. GRB 251016A: SVOM detection of a short burst
  51. GRB 251014A: Swift-XRT observations
  52. GRB 251014B: PRIME J-band upper limit
  53. Upper limits from a search for additional neutrino events in IceCube
  54. GRB 251013C: Kilonova-Catcher optical afterglow detection
  55. GRB 251013D: Swift/UVOT Observations
  56. GRB 251013C: Swift/UVOT Detection
  57. Konus-Wind detection of GRB 251007A
  58. Fermi Gamma-ray Burst Monitor trigger 782237334/251015673 is not a GRB
  59. GRB 251013C, GCN Circular 42267, errata corrige
  60. GRB 251013C: detection of a radio counterpart at 15.5GHz
  61. GRB 251015A: Fermi GBM Final Real-time Localization
  62. GRB 251013C: SVOM/ECLAIRs refined analysis
  63. GRB 251013D: Swift-XRT observations
  64. Swift Trigger 1404295: possible GRB 251015A
  65. GRB 251014B: Swift-XRT observations
  66. GRB 251014B: Swift/UVOT Upper Limits
  67. GRB 251014B: VLT/FORS2 Optical Observation
  68. GRB 251014D: Swift/UVOT Upper Limits
  69. GRB 251014D: BOOTES-6/DPRT optical upper limit
  70. GRB 251014D: Swift-XRT afterglow detection
  71. GRB 251013C: MAO/AZT-22 optical observations
  72. GRB 251011B: SVOM/VT optical upper limit
  73. GRB 251013C: Swift ToO observations
  74. GRB 251013D: Fermi GBM Observation
  75. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) further multi-band optical observations
  76. GRB 251014A: Swift-BAT refined analysis
  77. GRB 251013C: OHP/T193 further optical observations and possible color evolution
  78. GRB 251013C: Calapai Observatory, Massa S. Giorgio (Messina), optical observation
  79. GRB 251014D: Swift detection of a burst
  80. GRB 251014A: PRIME near-infrared upper limits
  81. GRB 251014C: Fermi GBM Final Localization
  82. GRB 251014A: Glowbug gamma-ray detection of a likely short burst
  83. GRB 251014A: VLT/FORS2 Optical Observation
  84. GRB 251013C: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an bright optical counterpart
  85. GRB 251012A: Glowbug gamma-ray detection of a likely short burst
  86. GRB 251013C: MarSEC, optical afterglow photometry
  87. GRB 251013C: OHP/T193 optical afterglow photometry and spectroscopy
  88. GRB 251014B: Swift ToO observations
  89. GRB 251013D: LAST optical upper limit on Swift/BAT-GUANO localization
  90. GRB 251014B: Swift/BAT-GUANO arcminute localization of a short burst
  91. GRB 251013C: Bassano Bresciano Observatory optical observations
  92. GRB 251013C: Early and late-time optical counterpart detection by LCO
  93. GRB 251013C: Fermi GBM Observation
  94. GRB 251013D: Swift ToO observations
  95. GRB 251014A: DDOTI Upper Limit
  96. GRB 251013C NUTTelA-TAO / BSTI Early Measurements
  97. GRB 251013C: ULL-ASTRO-MASTER detection of the optical afterglow with the LCO 40-cm telescope at Sutherland Observatory
  98. GRB 251013C: Asiago optical observations
  99. GRB 251013A: CALET Gamma-Ray Burst Monitor detection
  100. GRB 251013C: ABObservatory optical observations

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