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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.

Advanced Search Examples (click to copy):

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

21468 results found.

  1. GRB 231215A: Swift-XRT refined Analysis
  2. GRB 231215A: BOOTES-4/MET optical detection
  3. GRB 231215A: AKO Optical Upper Limit
  4. GRB 231215A: AGILE detection
  5. GRB 231214A: Fermi GBM observation
  6. Konus-Wind detection of GRB 231210B
  7. GRB 231215A: Enhanced Swift-XRT position
  8. GRB 231214A: REM optical/NIR upper limits
  9. GRB 231215A: GROWTH-India optical follow-up
  10. GRB 231215A : Nanshan/HMT optical observations
  11. GRB 231215A: AstroSat CZTI detection
  12. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  13. GRB 231214A: Swift-XRT refined Analysis
  14. GRB 231215A: Mondy optical bright afterglow detection
  15. GRB 231214A: AstroSat CZTI detection
  16. GRB 231215C: MASTER OT detection
  17. Swift GRB231215.41: Global MASTER-Net observations report
  18. GRB 231215A: Swift-XRT observations
  19. GRB 231215A: Swift detection of a burst
  20. GRB 231214A: Fermi-LAT detection
  21. GRB 231214A: Enhanced Swift-XRT position
  22. GRB 231214B: Swift/BAT-GUANO detection of a burst
  23. GRB231214A: BOOTES-6/DPRT optical upper limit
  24. Swift GRB231214.85: Global MASTER-Net observations report
  25. GRB 231214A: Swift detection of a burst
  26. GRB 231210B: REM optical/NIR upper limits
  27. LIGO/Virgo/KAGRA S231206cc: Upper limits from Swift/BAT-GUANO
  28. LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
  29. GRB 231210B: MeerLICHT afterglow observations
  30. GRB 231210B: Swift-BAT refined analysis
  31. GRB 231210B: Swift-XRT refined Analysis
  32. GRB 231210B: Enhanced Swift-XRT position
  33. GRB 231210B: VLT/X-shooter redshift
  34. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  35. GRB 231210B: Swift detection of a burst with optical counterpart
  36. Swift GRB231210.90: Global MASTER-Net OT detection
  37. Swift GRB231210.90: Global MASTER-Net observations report
  38. IPN triangulation of GRB 231129C
  39. GRB231205B: Swift/UVOT Upper Limits
  40. GRB 231205B: Swift-BAT refined analysis
  41. GRB 231205B: 1.3m DFOT Optical upper limit
  42. GRB 231205B: optical upper limit in TSHAOand AbAO
  43. GRB 231205B: AGILE detection
  44. GRB 231205B: Ondrejov D50 optical upper limit
  45. GRB 231205B: Swift-XRT refined Analysis
  46. GRB 231205B: REM optical/NIR upper limits
  47. GRB 231129C: ASIM MXGS observation and localization
  48. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  49. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  50. GRB 231205B : MITSuME Akeno optical upper limits
  51. GRB 231205B: Zadko observatory - Gingin optical observations
  52. GRB 231205B: Gaoyazi/GOT optical upper limit
  53. GRB 231205B: Nanshan/HMT optical upper limit
  54. GRB 231205B: GECAM-B detection of a long burst
  55. GRB 231205B: LCOGT Optical Upper Limits
  56. GRB 231205B: Enhanced Swift-XRT position
  57. Swift GRB231205.70: Global MASTER-Net observations report
  58. GRB 231205B: AKO Optical Upper Limit
  59. GRB 231205B: Swift detection of a burst
  60. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  61. GRB 231203A: Fermi GBM Observation
  62. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  63. Konus-Wind detection of GRB 231129C
  64. GRB 231129C: Swift-XRT afterglow detection
  65. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  66. GRB 231129A: VZLUSAT-2 detection
  67. GRB 231129B: Swift-XRT observations
  68. GRB 231129C: AGILE detection
  69. GRB 231129A : MITSuME Akeno optical upper limits
  70. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  71. GRB 231129A: Swift-BAT refined analysis
  72. GRB 231129C: MASTER OT detection
  73. GRB 231129A: BOOTES-5/JGT optical upper limit
  74. GRB 231129A: JinShan optical upper limit
  75. GRB 231129C: Swift-XRT observations
  76. GRB 231129A: Swift/UVOT Upper Limits
  77. GRB 231129A: optical upper limit in Mondy observatory
  78. GRB 231129C: Tiled Swift observations
  79. GRB 231129A: Enhanced Swift-XRT position
  80. GRB 231129A: Swift-XRT refined Analysis
  81. GRB 231129B: Tiled Swift observations
  82. GRB 231129A: GECAM-C detection of a long burst
  83. GRB 231129A: INTEGRAL detection of a long GRB
  84. GRB 231129A: Swift detection of a burst
  85. GRB 231123C: Fermi GBM Observation
  86. GRB 231123B: Fermi GBM Observation
  87. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  88. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  89. GRB 231123C: Insight-HXMT/HE detection
  90. GRB 231123C (short): Glowbug gamma-ray detection
  91. GRB230728A: VIRT optical upper limit
  92. GRB230506B: VIRT optical upper limit
  93. GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
  94. GRB 231115A: XMM-Newton observation
  95. GRB 231118A: REM optical afterglow detection
  96. GRB 231122B: AstroSat CZTI detection
  97. GRB 231122B: CALET Gamma-Ray Burst Monitor detection
  98. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  99. GRB 231117A: Chandra afterglow detection
  100. GRB 231118A: ATCA detection of radio counterpart

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