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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"

36269 results found.

  1. GRB 241228A: Swift detection of a burst
  2. GRB 241223A: GRBAlpha detection
  3. GRB 241212A: VZLUSAT-2 detection
  4. GRB 241217A/EP241217b: continued SOAR observations
  5. Fermi GRB 241226A: Global MASTER-Net observations report
  6. GRB 241226A: Fermi GBM Final Real-time Localization
  7. EP241223a: Mondy AZT-33IK optical observations
  8. GRB 241029A: LCO optical observation
  9. GRB 241223A: Swift-XRT observations
  10. GRB 241029A: AbAO AS-32 optical observations
  11. GRB 241223A: Fermi GBM Detection
  12. GRB 241219A: SVOM/GRM observation
  13. GRB241113A: 7DT Optical upper limits
  14. Fermi Gamma-ray Burst Monitor trigger 756678579 / 241223854 is not a GRB
  15. Fermi GRB 241223A: Global MASTER-Net observations report
  16. GRB 241223A: GOTO optical observations summary
  17. GRB 241105A: JWST photometric observations of the host galaxy
  18. GRB 241223A: Swift ToO observations
  19. GRB 241223A: BALROG localization (Fermi Trigger 756648531 / GRB 241223506)
  20. GRB 241223A: Fermi GBM Final Real-time Localization
  21. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  22. GRB 241209B: host galaxy detection and GTC/OSIRIS+ spectroscopy
  23. Fermi Gamma-ray Burst Monitor trigger 756447119/241221175 is not a GRB
  24. Fermi GRB 241221A: Global MASTER-Net observations report
  25. GRB 241221A: Fermi GBM Final Real-time Localization
  26. GRB 241217A/EP241217b: SOAR afterglow detection
  27. GRB 241218A: Mondy AZT-33IK optical upper limit
  28. EP241217a : Leavitt Observatory optical upper limit
  29. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  30. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  31. GRB 241218A: Swift/UVOT Upper Limits
  32. GRB 241209B: EP-FXT afterglow detection
  33. Konus-Wind detection of GRB 241204A (short/hard)
  34. GRB 241218A: NOT optical upper limits
  35. GRB 241218A: Swift-BAT refined analysis
  36. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  37. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  38. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  39. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  40. GRB 241217A / EP241217b: NOT optical upper limits
  41. GRB 241218A: REM optical upper limit
  42. GRB 241217A/EP241217b: REM optical/NIR upper limits
  43. GRB 241218a: Liverpool Telescope optical follow-up
  44. GRB 241217a: Liverpool Telescope optical follow-up
  45. GRB 241218A: Swift-XRT refined Analysis
  46. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  47. GRB 241209A: ATCA radio follow-up observations
  48. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  49. GRB 241218A: LCOGT Optical Upper Limit
  50. GRB 241218A: Enhanced Swift-XRT position
  51. GRB 241217A: GMG Optical Upper Limit
  52. GRB 241218A: Swift detection of a burst
  53. GRB 241217A : SVOM/VT optical afterglow detection
  54. GRB 241217A: Swift-XRT afterglow detection
  55. GRB 241217A: LCO optical upper limit
  56. GRB 241217A: GRANDMA/TAROT optical upperlimits
  57. EP241217A: Non-detection from Fermi-GBM Observations
  58. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  59. GRB 241214A: GRBAlpha detection
  60. GRB 241213A (EP241213a): GRBAlpha detection
  61. GRB 241209D: GRBAlpha detection
  62. GRB 241213A: Swift-BAT refined analysis
  63. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  64. Konus-Wind detection of GRB 241213A (EP 241213a)
  65. GRB 241215A: Mondy AZT-33IK optical observations
  66. GRB 241212A: Swift-XRT observations
  67. GRB 241214A: SVOM/GRM observation
  68. GRB 241215A: Nanshan/HMT optical upper limit
  69. GRB 241215A: Montarrenti Observatory optical upper limit
  70. GRB 241215A: GROWTH-India telescope optical upper limit
  71. GRB 241215A: A long GRB detected by INTEGRAL
  72. GRB 241213B: Swift-XRT observations
  73. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  74. GRB 241209B: SVOM/VT optical continuous fading
  75. GRB 241213A: SVOM/VT optical candidate
  76. GRB 241213B: Tiled Swift observations
  77. GRB 241213A: Swift/UVOT Upper Limits
  78. GRB 241213B: CALET Gamma-Ray Burst Monitor detection
  79. GRB 241213A: Swift-XRT refined Analysis
  80. GRB 241212A: Fermi GBM detection
  81. GRB 241212A: Swift ToO observations
  82. GRB 241213A: LCOGT Optical Upper Limits
  83. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  84. GRB 241213B: MAXI/GSC detection
  85. GRB 241213A: REM optical/NIR upper limits
  86. GRB 241213A: Enhanced Swift-XRT position
  87. GRB241212A: OHP/T193 optical observations
  88. GRB 241213A: SAO RAS optical upper limit
  89. Swift GRB 241213A: Global MASTER-Net observations report
  90. GRB 241213A: Swift detection of a burst
  91. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  92. GRB 241212A : SVOM/VT bright optical afterglow
  93. GRB 241212A: AstroSat CZTI detection
  94. GRB 241209B: GRANDMA/TRT upper limit
  95. GRB 241207A: TSHAO Zeiss-1000 optical observations
  96. GRB 241212A: SVOM detection of a bright long burst
  97. GRB 241212A: Fermi GBM Final Real-time Localization
  98. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  99. GRB 241209A: Chandra X-ray Detection
  100. Konus-Wind detection of GRB 241209B

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