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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.

Lucene Examples (click to copy):

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

3035 results found.

  1. GRB 241229A: EP-FXT afterglow candidates
  2. GRB 241228B: Swift-XRT afterglow detection
  3. GRB 241229B: Swift-XRT refined Analysis
  4. GRB 241228A: Swift-XRT refined Analysis
  5. GRB 241223A: Swift-XRT observations
  6. EP 241217a: NIR detection with P200/WIRC
  7. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  8. GRB 241218A: Swift-XRT refined Analysis
  9. GRB 241217A: Swift-XRT afterglow detection
  10. EP241217a: Swift-XRT Detection
  11. GRB 241212A: Swift-XRT observations
  12. GRB 241213B: Swift-XRT observations
  13. GRB 241213A: Swift-XRT refined Analysis
  14. EP241213a: EP detection of An X-ray Transient
  15. GRB 241209A: Chandra X-ray Detection
  16. GRB 241209B: Swift-XRT afterglow detection
  17. GRB 241209A: Swift-XRT refined Analysis
  18. EP241208a: EP-FXT follow-up observations
  19. GRB 241209D: Swift-XRT refined Analysis
  20. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  21. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  22. EP241201a: EP-FXT follow-up observations
  23. Fermi trigger No 754701230: Global MASTER-Net observations report
  24. Swift-XRT observations of IceCube -241127A
  25. GRB 241128A: Swift-XRT refined Analysis
  26. GRB 241128A: Swift-XRT afterglow detection
  27. GRB 241127A: Swift-XRT refined Analysis
  28. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  29. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  30. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  31. GRB 241115A: Swift-XRT afterglow detection
  32. GRB 241113B: Swift-XRT observations
  33. GRB 241113A: Swift-XRT refined Analysis
  34. GRB 241112B: Swift-XRT afterglow detection
  35. GRB 241108A: Swift-XRT observations
  36. GRB 241105A: Swift/UVOT Detection
  37. GRB 241105A: Swift-XRT afterglow detection
  38. GRB 241104A: Swift-XRT observations
  39. EP241104a: EP detection of GRB 241104A X-ray emission
  40. EP241101a: EP-FXT observations update
  41. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  42. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  43. EP241101a: EP-WXT detection of a fast X-ray transient
  44. GRB 241030B: Swift-XRT refined Analysis
  45. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  46. GRB 241029A: SVOM/VT optical afterglow observations
  47. EP241021a: Swift-UVOT detection
  48. GRB 241030A: Swift-XRT refined Analysis
  49. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  50. GRB 241029A: Swift-XRT observations
  51. GRB 241026A: Swift-XRT refined Analysis
  52. GRB 241025A: Swift-XRT refined Analysis
  53. EP 241021a: Swift-XRT observations
  54. GRB 241018A: Swift-XRT observations
  55. GRB 241017A: Swift-XRT observations
  56. GRB 241001A: EP-FXT afterglow detection
  57. GRB 241009A: Swift-XRT afterglow detection
  58. GRB 241010A: Swift-XRT refined Analysis
  59. GRB 241002B: Swift-XRT afterglow detection
  60. GRB 241006A: Swift-XRT refined Analysis
  61. GRB 241001A: Swift-XRT afterglow detection
  62. GRB 241002B: Swift-XRT observations
  63. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  64. GRB 241002A: Swift-XRT refined Analysis
  65. GRB 241001A: Swift-XRT observations
  66. EP240919a / GRB 240919A: SVOM/VT upper limit
  67. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  68. GRB 240910A: further Swift observations and confirmation of afterglow
  69. GRB 240916A: Swift-XRT afterglow detection
  70. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  71. EP240913a: VLT/HAWK-I near-infrared upper limits
  72. GRB 240914A: Swift-XRT observations
  73. GRB 240910A: SVOM/VT optical observations
  74. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  75. GRB 240911A: Swift-XRT observations
  76. GRB 240912A: Swift-XRT refined Analysis
  77. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  78. GRB 240905E: SVOM/VT optical observations
  79. EP240908a: EP detection of a fast X-ray transient
  80. GRB 240905B: Swift-XRT observations
  81. GRB 240905E: Swift-XRT refined Analysis
  82. GRB 240905B: AstroSat CZTI detection and localization
  83. GRB 240828A: Swift-XRT afterglow detection
  84. GRB 240828B: Swift-XRT afterglow detection
  85. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  86. GRB 240819A: Swift afterglow confirmation
  87. GRB 240825A: Swift-XRT refined Analysis
  88. GRB 240824B: Swift-XRT afterglow detection
  89. GRB 240824A: Swift-XRT observations
  90. GRB 240821A: Swift/UVOT observations of the XRT sources.
  91. GRB 240821A: Swift-XRT observations
  92. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  93. GRB 240819A: Swift-XRT observations
  94. EP240820a: EP detection of a fast X-ray transient
  95. GRB 240819A: X-ray follow-up observation with EP-FXT
  96. GRB 240811A: Swift-XRT refined Analysis
  97. GRB 240809A: Swift-XRT refined Analysis
  98. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  99. GRB 240805B: Swift-XRT refined Analysis
  100. GRB 240805A: Swift-XRT refined Analysis

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