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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"

26119 results found.

  1. GRB 241229A: SAO RAS optical observations
  2. GRB 241229B: SVOM/VT optical candidate
  3. GRB 241229A: Swift-XRT observations
  4. Konus-Wind detection of GRB 241228A
  5. GRB 241229A: EP-FXT afterglow candidates
  6. GRB 240606B: 7DT Optical upper limits
  7. GRB 241229B: Swift-BAT refined analysis
  8. GRB241229B: UVOT upper limits
  9. GRB 241228B: D50 optical detection
  10. GRB 241228B: Fermi GBM Observation
  11. GRB 241228B: Swift-XRT afterglow detection
  12. GRB 241229B: Fermi GBM Observation
  13. GRB 241229A: Swift ToO observations
  14. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  15. GRB 241228A: Mondy optical afterglow observations
  16. GRB 241229B: Swift-XRT refined Analysis
  17. Swift GRB 241229B: Global MASTER-Net observations report
  18. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  19. GRB 241228A: NOT optical upper limits
  20. GRB 241228A: Swift-BAT refined analysis
  21. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  22. GRB 241229B: Swift detection of a burst
  23. GRB 241228A: Fermi GBM Observation
  24. GRB241228B: GROWTH-India Telescope optical observations
  25. Swift GRB 241228A: Global MASTER-Net observations report
  26. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  27. GRB 241228A: GROWTH-India telescope optical upper limit
  28. GRB 241228B: Swift ToO observations
  29. GRB 241228A: Swift-XRT refined Analysis
  30. GRB 241228A: Swift/UVOT Upper Limits
  31. GRB 241228A: Enhanced Swift-XRT position
  32. GRB 241228A: Swift detection of a burst
  33. GRB 241223A: Swift-XRT observations
  34. GRB241113A: 7DT Optical upper limits
  35. GRB 241223A: GOTO optical observations summary
  36. GRB 241105A: JWST photometric observations of the host galaxy
  37. GRB 241223A: Swift ToO observations
  38. GRB 241209B: host galaxy detection and GTC/OSIRIS+ spectroscopy
  39. GRB 241217A/EP241217b: SOAR afterglow detection
  40. GRB 241218A: Mondy AZT-33IK optical upper limit
  41. EP241217a : Leavitt Observatory optical upper limit
  42. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  43. GRB 241218A: Swift/UVOT Upper Limits
  44. EP241217a: optical upper limit with the Liverpool Telescope
  45. GRB 241209B: EP-FXT afterglow detection
  46. GRB 241218A: NOT optical upper limits
  47. GRB 241218A: Swift-BAT refined analysis
  48. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  49. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  50. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  51. GRB 241217A / EP241217b: NOT optical upper limits
  52. GRB 241218A: REM optical upper limit
  53. GRB 241217A/EP241217b: REM optical/NIR upper limits
  54. EP241217a: REM optical/NIR upper limits
  55. GRB 241218a: Liverpool Telescope optical follow-up
  56. GRB 241217a: Liverpool Telescope optical follow-up
  57. GRB 241218A: Swift-XRT refined Analysis
  58. GRB 241209A: ATCA radio follow-up observations
  59. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  60. GRB 241218A: LCOGT Optical Upper Limit
  61. GRB 241218A: Enhanced Swift-XRT position
  62. GRB 241218A: Swift detection of a burst
  63. GRB 241217A : SVOM/VT optical afterglow detection
  64. GRB 241217A: Swift-XRT afterglow detection
  65. GRB 241217A: LCO optical upper limit
  66. GRB 241217A: GRANDMA/TAROT optical upperlimits
  67. EP241217a: Swift-XRT Detection
  68. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  69. GRB 241214A: GRBAlpha detection
  70. GRB 241213A (EP241213a): GRBAlpha detection
  71. GRB 241209D: GRBAlpha detection
  72. GRB 241213A: Swift-BAT refined analysis
  73. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  74. Konus-Wind detection of GRB 241213A (EP 241213a)
  75. GRB 241212A: Swift-XRT observations
  76. GRB 241213B: Swift-XRT observations
  77. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  78. GRB 241213A: SVOM/VT optical candidate
  79. GRB 241213B: Tiled Swift observations
  80. GRB 241213A: Swift/UVOT Upper Limits
  81. GRB 241213A: Swift-XRT refined Analysis
  82. GRB 241212A: Swift ToO observations
  83. GRB 241213A: LCOGT Optical Upper Limits
  84. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  85. EP241213a: EP detection of An X-ray Transient
  86. GRB 241213A: REM optical/NIR upper limits
  87. GRB 241213A: Enhanced Swift-XRT position
  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/VT bright optical afterglow
  92. GRB 241209B: GRANDMA/TRT upper limit
  93. GRB 241209A: Chandra X-ray Detection
  94. Konus-Wind detection of GRB 241209B
  95. GRB 241209B: GRBAlpha detection
  96. GRB 241129A: Fermi GBM Observation
  97. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  98. GRB 241209D: REM optical/NIR upper limits
  99. Konus-Wind detection of GRB 241209D
  100. GRB 241209B: Swift-XRT afterglow detection

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