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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"

37715 results found.

  1. GRB 241218A: LCOGT Optical Upper Limit
  2. GRB 241218A: Enhanced Swift-XRT position
  3. GRB 241217A: GMG Optical Upper Limit
  4. GRB 241218A: Swift detection of a burst
  5. GRB 241217A : SVOM/VT optical afterglow detection
  6. GRB 241217A: Swift-XRT afterglow detection
  7. GRB 241217A: LCO optical upper limit
  8. GRB 241217A: GRANDMA/TAROT optical upperlimits
  9. EP241217A: Non-detection from Fermi-GBM Observations
  10. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  11. GRB 241214A: GRBAlpha detection
  12. GRB 241213A (EP241213a): GRBAlpha detection
  13. GRB 241209D: GRBAlpha detection
  14. GRB 241213A: Swift-BAT refined analysis
  15. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  16. Konus-Wind detection of GRB 241213A (EP 241213a)
  17. GRB 241215A: Mondy AZT-33IK optical observations
  18. GRB 241212A: Swift-XRT observations
  19. GRB 241214A: SVOM/GRM observation
  20. GRB 241215A: Nanshan/HMT optical upper limit
  21. GRB 241215A: Montarrenti Observatory optical upper limit
  22. GRB 241215A: GROWTH-India telescope optical upper limit
  23. GRB 241215A: A long GRB detected by INTEGRAL
  24. GRB 241213B: Swift-XRT observations
  25. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  26. GRB 241209B: SVOM/VT optical continuous fading
  27. GRB 241213A: SVOM/VT optical candidate
  28. GRB 241213B: Tiled Swift observations
  29. GRB 241213A: Swift/UVOT Upper Limits
  30. GRB 241213B: CALET Gamma-Ray Burst Monitor detection
  31. GRB 241213A: Swift-XRT refined Analysis
  32. GRB 241212A: Fermi GBM detection
  33. GRB 241212A: Swift ToO observations
  34. GRB 241213A: LCOGT Optical Upper Limits
  35. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  36. GRB 241213B: MAXI/GSC detection
  37. GRB 241213A: REM optical/NIR upper limits
  38. GRB 241213A: Enhanced Swift-XRT position
  39. GRB241212A: OHP/T193 optical observations
  40. GRB 241213A: SAO RAS optical upper limit
  41. Swift GRB 241213A: Global MASTER-Net observations report
  42. GRB 241213A: Swift detection of a burst
  43. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  44. GRB 241212A : SVOM/VT bright optical afterglow
  45. GRB 241212A: AstroSat CZTI detection
  46. GRB 241209B: GRANDMA/TRT upper limit
  47. GRB 241207A: TSHAO Zeiss-1000 optical observations
  48. GRB 241212A: SVOM detection of a bright long burst
  49. GRB 241212A: Fermi GBM Final Real-time Localization
  50. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  51. GRB 241209A: Chandra X-ray Detection
  52. Konus-Wind detection of GRB 241209B
  53. GRB 241207A: EIRSAT-1 GMOD Detection
  54. GRB 241209A: Redshift of the likely host galaxy z = 0.784 from OSIRIS+/GTC
  55. GRB 241209B: GRBAlpha detection
  56. GRB 241206C: GRBAlpha detection
  57. GRB 241211A: Fermi GBM Final Real-time Localization
  58. GRB 241129A: Fermi GBM Observation
  59. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  60. GRB 241209D: REM optical/NIR upper limits
  61. Konus-Wind detection of GRB 241209D
  62. GRB 241209B: Swift-XRT afterglow detection
  63. GRB 241209C: Fermi GBM Observation
  64. GRB 241209A: Swift-XRT refined Analysis
  65. Fermi Gamma-ray Burst Monitor trigger 755485387 / 241210044 is not a GRB
  66. GRB 241128A: CrAO ZTSh and Mondy AZT-33IK optical observations
  67. GRB 241209D: AstroSat CZTI detection
  68. GRB 241209A: EP-FXT follow-up observations
  69. GRB 241209B: SVOM/VT afterglow detection
  70. Fermi trigger No 755485387: Global MASTER-Net observations report
  71. GRB 241207B: Fermi GBM Observation
  72. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  73. GRB 241209D: Swift-XRT refined Analysis
  74. GRB 241209D: Fermi GBM Observation
  75. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  76. GRB 241209D: COLIBRÍ detection of the afterglow
  77. GRB 241209A: COLIBRÍ Optical Upper Limit
  78. Fermi GRB 241209D: Global MASTER-Net observations report
  79. GRB 241209A: Fermi GBM Observation
  80. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  81. GRB 241209A: GRANDMA/TAROT upper limit
  82. GRB 241209B: BOOTES-5 optical upper limit
  83. Swift GRB 241209D: Global MASTER-Net observations report
  84. Fermi GRB 241209C: Global MASTER-Net observations report
  85. Fermi GRB 241209E: Global MASTER-Net observations report
  86. GRB 241209E: Fermi GBM Final Real-time Localization
  87. GRB 241209B: Swift ToO observations
  88. GRB 241209A: REM optical/NIR observations
  89. GRB 241209D: Enhanced Swift-XRT position
  90. GRB 241209C: AstroSat CZTI detection
  91. GRB 241209D: Swift detection of a burst
  92. GRB 241209D: Fermi GBM Final Real-time Localization
  93. GRB 241209A: VLT/X-shooter spectroscopy
  94. GRB 241209A: Enhanced Swift-XRT position
  95. GRB 241114B: cubesat Avion detection
  96. GRB 241209A: VLT optical observations
  97. Fermi GRB 241209A: Global MASTER-Net observations report
  98. GRB 241209C: Fermi GBM Final Real-time Localization
  99. GRB 241209A: GOTO optical upper limits
  100. GRB 241209A: Prompt enhanced Swift-XRT position

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