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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

36135 results found.

  1. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  2. GRB 231214A: Swift-XRT refined Analysis
  3. GRB 231215A: Mondy optical bright afterglow detection
  4. GRB 231214A: AstroSat CZTI detection
  5. GRB 231215C: MASTER OT detection
  6. GRB 231215A: Swift-XRT observations
  7. GRB 231215B: Fermi GBM Final Real-time Localization
  8. GRB 231215A: Swift detection of a burst
  9. GRB 231214A: Fermi-LAT detection
  10. GRB 231214A: Enhanced Swift-XRT position
  11. GRB 231214B: Swift/BAT-GUANO detection of a burst
  12. GRB231214A: BOOTES-6/DPRT optical upper limit
  13. GRB 231214A: Swift detection of a burst
  14. GRB 231214A: Fermi GBM Final Real-time Localization
  15. GRB 231210B: REM optical/NIR upper limits
  16. IceCube-231211A: Upper limits from a search for additional neutrino events in IceCube
  17. LIGO/Virgo/KAGRA S231206cc: Upper limits from Swift/BAT-GUANO
  18. LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
  19. GRB 231212A: GECAM-C detection of a likely short burst
  20. GRB 231210B: MeerLICHT afterglow observations
  21. GRB 231210B: Swift-BAT refined analysis
  22. GRB 231210B: Swift-XRT refined Analysis
  23. GRB 231210B: Enhanced Swift-XRT position
  24. GRB 231210B: VLT/X-shooter redshift
  25. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  26. GRB 231210B: Swift detection of a burst with optical counterpart
  27. IPN triangulation of GRB 231129C
  28. GRB 231210A: Fermi GBM Final Real-time Localization
  29. GRB 231208A: GRBAlpha detection
  30. GRB231205B: Swift/UVOT Upper Limits
  31. GRB 231208A: Glowbug gamma-ray detection
  32. GRB 231208A: AstroSat CZTI detection of a faint burst
  33. IPN triangulation of GRB 231205A
  34. GRB 231205B: Swift-BAT refined analysis
  35. GRB 231205B: 1.3m DFOT Optical upper limit
  36. GRB 231206A: joint location of multiple instruments by ETJASMIN
  37. GRB 231205B: optical upper limit in TSHAOand AbAO
  38. GRB231115A: TURBO Pre-Burst Optical Upper Limits
  39. GRB 231205B: AGILE detection
  40. GRB 231206B: Fermi GBM Final Real-time Localization
  41. GRB 231205B: Ondrejov D50 optical upper limit
  42. GRB 231205B: Swift-XRT refined Analysis
  43. GRB 231205B: REM optical/NIR upper limits
  44. GRB 231129C: ASIM MXGS observation and localization
  45. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  46. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  47. GRB 231206A: GECAM-B detection of a short burst (correction)
  48. GRB 231205B : MITSuME Akeno optical upper limits
  49. GRB 231206A: GECAM-B detection of a short burst
  50. GRB 231205B: Zadko observatory - Gingin optical observations
  51. GRB 231205B: Gaoyazi/GOT optical upper limit
  52. GRB 231205B: Nanshan/HMT optical upper limit
  53. GRB 231205B: GECAM-B detection of a long burst
  54. GRB 231205B: LCOGT Optical Upper Limits
  55. GRB 231205A: DDOTI Upper Limits on the Afterglow
  56. GRB 231205B: Enhanced Swift-XRT position
  57. GRB 231204A: Glowbug gamma-ray detection
  58. GRB 231204A: CALET Gamma-Ray Burst Monitor detection
  59. GRB 231205B: AKO Optical Upper Limit
  60. GRB 231205B: Swift detection of a burst
  61. GRB 231205A: joint location of multiple instruments by ETJASMIN
  62. GRB 231204A: AstroSat CZTI detection
  63. GRB 231205A: GECAM-B detection of a short burst
  64. GRB 231205A: Fermi GBM Final Real-time Localization
  65. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  66. IceCube-231202A: Upper limits from a search for additional neutrino events in IceCube
  67. GRB 231203A: Fermi GBM Observation
  68. GRB 231204A: Fermi GBM Final Real-time Localization
  69. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  70. Konus-Wind detection of GRB 231129C
  71. The Fermi GBM team reports the detection of a likely SHORT GRB
  72. GRB 231203A: Fermi GBM Final Real-time Localization
  73. GRB 231129C: Swift-XRT afterglow detection
  74. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  75. GRB 231129A: VZLUSAT-2 detection
  76. GRB 231129B: Swift-XRT observations
  77. GRB 231128A: VZLUSAT-2 detection
  78. GRB 231129C: AGILE detection
  79. GRB 231129A : MITSuME Akeno optical upper limits
  80. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  81. GRB 231129A: Swift-BAT refined analysis
  82. GRB 231129C: MASTER OT detection
  83. GRB 231129A: BOOTES-5/JGT optical upper limit
  84. GRB 231129C: Fermi-LAT detection
  85. GRB 231129A: JinShan optical upper limit
  86. GRB 231129C: GRBAlpha detection
  87. GRB 231129C: Glowbug gamma-ray detection
  88. GRB 231129C: Swift-XRT observations
  89. GRB 231129A: Swift/UVOT Upper Limits
  90. GRB 231129A: optical upper limit in Mondy observatory
  91. GRB 231129C: GECAM-B detection of a bright burst
  92. GRB 231129C: AstroSat CZTI detection
  93. GRB 231129C: iTelescope OT retraction
  94. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  95. GRB 231129C: Fermi GBM Observation of a very bright GRB
  96. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  97. GRB 231129C: Tiled Swift observations
  98. GRB 231127A: GRBAlpha detection
  99. GRB 231129C: MAXI/GSC detection
  100. GRB 231129C: BALROG localization (Fermi Trigger / GRB 231129799)

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