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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"

32763 results found.

  1. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  2. GRB 251022A: GROWTH-India Telescope optical observations
  3. EP251023a: GROWTH-India Telescope optical observations
  4. GRB 251022A: Fermi GBM Observation
  5. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  6. GRB 251023A: Glowbug gamma-ray detection
  7. GRB 251023B: Glowbug gamma-ray detection
  8. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  9. EP251023a: Global MASTER-Net observations report
  10. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  11. IPN triangulation of GRB 251016B
  12. GRB 251023B: CALET Gamma-Ray Burst Monitor detection
  13. EP#01709247298: Swift-XRT counterpart detection
  14. EP251023a: COLIBRÍ optical observations
  15. GRB 251013C: further SAO RAS optical observations
  16. EP251023a: Keck/LRIS spectroscopic redshift z=2.232
  17. GRB 251022A: COLIBRÍ optical observations
  18. GRB 251013C: ISON-Castelgrande observatory optical observations
  19. GRB 251022A: MASTER OT detection
  20. GRB 251022A: DDOTI Optical Detection
  21. EP251021b/GRB 251021A: SVOM/VT optical candidate
  22. EP251023a: NOT optical counterpart detection
  23. Fermi GRB 251023A: Global MASTER-Net observations report
  24. EP251023a: GSP Optical Counterpart Detection
  25. EP251023a: Einstein Probe detection of an X-ray transient
  26. GRB 251022A: GOTO optical counterpart detection
  27. GRB 251022A: Fermi-LAT detection
  28. GRB 251022A: Tiled Swift observations
  29. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  30. EP251021b: BOOTES-7 optical upper limit
  31. GRB 250911A: MAXI/GSC detection
  32. LIGO/Virgo/KAGRA S251021u: Updated Sky localization
  33. GRB 251016A: SVOM/ECLAIRs refined analysis
  34. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  35. LIGO/Virgo/KAGRA S251018bi: Updated Sky localization
  36. Fermi-LAT gamma-ray observations of IceCube-251018A
  37. GRB 251017A : RAPAS follow-up observations
  38. IceCube-251018A: Upper limits from a search for additional neutrino events in IceCube
  39. GRB 251017A: COLIBRÍ optical observations of a late plateau
  40. IceCube-251018A: DDOTI Optical Upper Limit
  41. GRB 251017A: Swift-BAT refined analysis
  42. GRB 251016A: Fermi GBM Observation
  43. GRB 251018A: Fermi GBM Observation
  44. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  45. GRB 251016A: HXMT/HE detection
  46. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  47. GRB 251017A: Swift/UVOT Detection
  48. GRB 251016A: Swift/UVOT Detection
  49. GRB 251018A: Swift/UVOT Detection
  50. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event (duplicate submission)
  51. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  52. GRB 251016A: VLT/FORS2 Optical Observation
  53. GRB 251017A: COLIBRÍ photometric redshift
  54. GRB 251018A: MASTER OT detection
  55. GRB 251018A: TRT optical afterglow detection
  56. Swift GRB 251018A: Global MASTER-Net observations report
  57. GRB 251017A: SVOM/VT optical observation
  58. GRB 251011A: Fermi GBM Observation
  59. GRB 251017A: OHP/T193 i-band observations
  60. GRB 251013C: OHP/T193 third epoch optical observations and detected rebrightening
  61. GRB 251017A: J-band detection with WINTER
  62. GRB 251017A: Glowbug gamma-ray detection
  63. GRB 251013C: Liverpool Telescope observations
  64. GRB 251013C: Leavitt Observatory optical photometry
  65. Fermi GRB 251016B: Global MASTER-Net observations report
  66. GRB 251017A: JinShan observations of the optical afterglow
  67. Swift GRB 251017A: Global MASTER-Net observations report
  68. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  69. Swift Trigger 1404295 is not a GRB
  70. GRB 251016A: AstroSat CZTI detection of a short burst
  71. GRB 251017A: COLIBRÍ Early Afterglow Detection
  72. GRB 251016B: AstroSat CZTI detection
  73. GRB 251017A: BOOTES-5/JGT early optical afterglow detection
  74. GRB 251016A: CALET Gamma-Ray Burst Monitor detection
  75. GRB 251016B: CALET Gamma-Ray Burst Monitor detection
  76. GRB 251013C: JinShan observations of the non-thermal rebrightening of the optical counterpart
  77. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
  78. GRB 251007B: Swift-BAT refined analysis
  79. GRB 251014D: Swift-BAT refined analysis
  80. GRB 251016A: BOOTES-6/DPRT optical upper limit
  81. GRB 251016A: Glowbug gamma-ray detection of a short burst
  82. GRB 251013C: VLA detection
  83. Fermi GRB 251016A: Global MASTER-Net observations report
  84. LIGO/Virgo/KAGRA S251014cn: Updated Sky localization
  85. GRB 251014B: PRIME J-band upper limit
  86. Upper limits from a search for additional neutrino events in IceCube
  87. GRB 251013C: Kilonova-Catcher optical afterglow detection
  88. Fermi-LAT Gamma-ray Observations of IceCube-251014A
  89. GRB 251013D: Swift/UVOT Observations
  90. GRB 251013C: Swift/UVOT Detection
  91. Konus-Wind detection of GRB 251007A
  92. GRB 251013C, GCN Circular 42267, errata corrige
  93. GRB 251013C: detection of a radio counterpart at 15.5GHz
  94. GRB 251013C: SVOM/ECLAIRs refined analysis
  95. GRB 251014B: Swift/UVOT Upper Limits
  96. GRB 251014B: VLT/FORS2 Optical Observation
  97. GRB 251014D: Swift/UVOT Upper Limits
  98. GRB 251013C: MAO/AZT-22 optical observations
  99. GRB 251011B: SVOM/VT optical upper limit
  100. GRB 251013D: Fermi GBM Observation

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