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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"

28115 results found.

  1. EP241217a: Liverpool Telescope optical follow-up
  2. GRB 241218A: Swift-XRT refined Analysis
  3. EP241119a: 7DT Optical upper limits
  4. GRB 241209A: ATCA radio follow-up observations
  5. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  6. GRB 241218A: LCOGT Optical Upper Limit
  7. GRB 241218A: Enhanced Swift-XRT position
  8. GRB 241218A: Swift detection of a burst
  9. GRB 241217A : SVOM/VT optical afterglow detection
  10. GRB 241217A: Swift-XRT afterglow detection
  11. GRB 241217A: LCO optical upper limit
  12. GRB 241217A: GRANDMA/TAROT optical upperlimits
  13. EP241217a: Swift-XRT Detection
  14. EP241217A: Non-detection from Fermi-GBM Observations
  15. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  16. EP241217a: Gemini-North spectroscopic redshift z = 4.59
  17. GRB 241214A: GRBAlpha detection
  18. GRB 241213A (EP241213a): GRBAlpha detection
  19. GRB 241209D: GRBAlpha detection
  20. EP241217a: Gemini-North detection of the likely optical counterpart
  21. EP241217a: EP detection of an X-ray transient
  22. Konus-Wind detection of GRB 241213A (EP 241213a)
  23. GRB 241212A: Swift-XRT observations
  24. GRB 241213B: Swift-XRT observations
  25. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  26. GRB 241213A: SVOM/VT optical candidate
  27. GRB 241213B: Tiled Swift observations
  28. GRB 241213A: Swift/UVOT Upper Limits
  29. GRB 241213B: CALET Gamma-Ray Burst Monitor detection
  30. GRB 241213A: Swift-XRT refined Analysis
  31. GRB 241212A: Fermi GBM detection
  32. GRB 241212A: Swift ToO observations
  33. GRB 241213A: LCOGT Optical Upper Limits
  34. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  35. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  36. GRB 241213B: MAXI/GSC detection
  37. EP241213a: EP detection of An X-ray Transient
  38. GRB 241213A: REM optical/NIR upper limits
  39. GRB 241213A: Enhanced Swift-XRT position
  40. GRB241212A: OHP/T193 optical observations
  41. GRB 241213A: SAO RAS optical upper limit
  42. GRB 241213A: Swift detection of a burst
  43. GRB 241212A : SVOM/VT bright optical afterglow
  44. GRB 241212A: AstroSat CZTI detection
  45. GRB 241209B: GRANDMA/TRT upper limit
  46. GRB 241212A: SVOM detection of a bright long burst
  47. GRB 241212A: Fermi GBM Final Real-time Localization
  48. GRB 241209A: Chandra X-ray Detection
  49. Konus-Wind detection of GRB 241209B
  50. GRB 241207A: EIRSAT-1 GMOD Detection
  51. GRB 241209B: GRBAlpha detection
  52. GRB 241206C: GRBAlpha detection
  53. GRB 241211A: Fermi GBM Final Real-time Localization
  54. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  55. GRB 241209D: REM optical/NIR upper limits
  56. Konus-Wind detection of GRB 241209D
  57. GRB 241209B: Swift-XRT afterglow detection
  58. GRB 241209A: Swift-XRT refined Analysis
  59. GRB 241128A: CrAO ZTSh and Mondy AZT-33IK optical observations
  60. GRB 241209D: AstroSat CZTI detection
  61. GRB 241209A: EP-FXT follow-up observations
  62. GRB 241209B: SVOM/VT afterglow detection
  63. EP241208a: EP-FXT follow-up observations
  64. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  65. GRB 241209D: Swift-XRT refined Analysis
  66. GRB 241209D: COLIBRÍ detection of the afterglow
  67. GRB 241209A: Fermi GBM Observation
  68. GRB 241209A: GRANDMA/TAROT upper limit
  69. GRB 241209B: BOOTES-5 optical upper limit
  70. GRB 241209E: Fermi GBM Final Real-time Localization
  71. GRB 241209B: Swift ToO observations
  72. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  73. GRB 241209A: REM optical/NIR observations
  74. GRB 241209D: Enhanced Swift-XRT position
  75. GRB 241209C: AstroSat CZTI detection
  76. GRB 241209D: Swift detection of a burst
  77. GRB 241209D: Fermi GBM Final Real-time Localization
  78. GRB 241209A: Enhanced Swift-XRT position
  79. GRB 241114B: cubesat Avion detection
  80. GRB 241209A: VLT optical observations
  81. GRB 241209C: Fermi GBM Final Real-time Localization
  82. GRB 241209A: GOTO optical upper limits
  83. EP241206a: 1.5m OSN optical limit
  84. GRB 241209A: Prompt enhanced Swift-XRT position
  85. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  86. EP241208a: EP detection of a fast X-ray transient
  87. GRB 241209A: Swift detection of a short burst
  88. GRB 241209A: Fermi GBM Final Real-time Localization
  89. GRB 241201A: AstroSat CZTI detection
  90. GRB 241206A: DDOTI Upper Limit on the Afterglow
  91. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  92. EP241206a: BOOTES Global Network optical limits
  93. GRB 241207C: Tiled Swift observations
  94. GRB 241207C: MAXI/GSC detection
  95. GRB 241207B: Fermi GBM Final Real-time Localization
  96. EP241206a: EP detection of a fast X-ray transient
  97. GRB 241207A: Fermi GBM Final Real-time Localization
  98. GRB 241206B: SVOM/ECLAIRs detection of a long soft transient
  99. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  100. GRB 241206A: Fermi GBM Final Real-time Localization

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