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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"

3322 results found.

  1. EP241113a: No Detection in Fermi-GBM Observations
  2. EP 241113a: LBT possible optical counterpart
  3. GRB 241113B: KAIT Optical Afterglow Candidate
  4. EP241113a: Global MASTER-Net observations report
  5. EP241113a : J-band observations with WINTER
  6. EP241113b: Global MASTER-Net observations report
  7. EP241113b/GRB 241113B: EP detection of GRB 241113B
  8. EP241113a: EP on-board trigger and autonomous follow-up observation
  9. Konus-Wind detection of GRB 241107A (short/hard)
  10. EP241107a: EP-FXT follow-up observations
  11. GRB 241025A: VZLUSAT-2 detection
  12. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  13. EP241109a: confirmation of a stellar flare by BOOTES-7
  14. EP241109a: EP on-board trigger and autonomous follow-up observation
  15. EP241107A: MASTER optical observations of xray transient
  16. EP241107a: Kinder optical follow-up observations
  17. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  18. EP241107a: AKO Optical Afterglow Follow-Up Observations
  19. EP241107a: GSP detects optical counterpart
  20. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  21. GRB 241105A: EP-FXT follow-up observations
  22. EP241107a: GIT optical observations
  23. EP241107a: Global MASTER-Net observations report
  24. EP241107a: SVOM/C-GFT optical observations
  25. EP241107a: AKO Optical Afterglow Detection
  26. EP241107a: EP on-board trigger and autonomous follow-up observation
  27. EP241101a: CrAO ZTSH optical observations
  28. Konus-Wind detection of GRB 241105A (short with extended emission)
  29. Konus-Wind detection of GRB 241021A
  30. GRB 241104A: Swift-XRT observations
  31. GRB 241104A: Fermi GBM Observation
  32. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  33. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  34. EP241104a: EP detection of GRB 241104A X-ray emission
  35. EP241101a: EP-FXT observations update
  36. EP241103a: GOTO optical upper limit
  37. EP241101a: Possible detection of an optical counterpart with FTW
  38. EP241103a: Swift XRT detection and improved X-ray position
  39. EP241101a: Optical upper limits with Kinder observations
  40. EP241103a: Gemini optical limits
  41. EP241103a: EP observation update
  42. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  43. EP241103a: GSP optical upper limit
  44. EP241103A: LCO optical observations
  45. EP241103a: Global MASTER-Net observations report
  46. EP241103a: an X-ray transient detected by Einstein Probe
  47. EP241101a: Global MASTER-Net observations report
  48. EP241101a: BOOTES-7 optical upper limit
  49. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  50. EP241101a: EP-WXT detection of a fast X-ray transient
  51. EP241021a: Upper limit from Konus-Wind observations
  52. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  53. EP EP241030a: Global MASTER-Net observations report
  54. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  55. EP241021a: Swift-UVOT detection
  56. Konus-Wind detection of GRB 241030A
  57. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  58. EP241026b: EP-FXT follow-up observation
  59. EP241021a: ATCA radio observations
  60. EP 241026b: LBT possible optical counterpart (brightening source)
  61. GRB 241026A: the 100th GRB detected by GRBAlpha
  62. Konus-Wind detection of GRB 241025A
  63. GRB 241026A: GECAM detection
  64. GRB 241026A: SVOM/GRM observation
  65. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  66. EP 241026b: LBT optical observations
  67. EP241021a: e-MERLIN radio observation
  68. EP EP241026b: Global MASTER-Net observations report
  69. EP241026b: EP detection of a fast X-ray transient
  70. EP241021a: optical follow-up observations with Xinglong Observatory
  71. EP 241021a: Swift-XRT observations
  72. EP241021a: optical follow-up observations with the Liverpool Telescope
  73. EP241025a (GRB 241025A): EP observations update
  74. EP 241021A: Swift ToO observations
  75. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  76. GRB 241025A: TRT optical afterglow observation
  77. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  78. EP241021a: No Detection in Fermi-GBM Observation
  79. EP241021a: VLT/FORS2 redshift z = 0.75
  80. EP241021a: EP-FXT follow-up observation update
  81. EP241021a: Optical counterpart observations with the Liverpool Telescope
  82. EP241021a: Optical upper limits with Kinder observations
  83. EP241021a: TRT optical observations
  84. EP241021a: NOT likely optical counterpart
  85. EP EP241021a: Global MASTER-Net observations report
  86. GRB 241018A: EP-FXT afterglow detection
  87. EP241021a: GOTO optical upper limits
  88. EP241021a: EP detection of a fast X-ray transient
  89. Konus-Wind detection of GRB 241018A
  90. GRB 241001A: EP-FXT afterglow detection
  91. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  92. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  93. GRB 240930B: SVOM/C-GFT optical upper limit
  94. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  95. GRB 240930B / EP 240930a: SVOM/GRM observation
  96. Konus-Wind detection of GRB 240926A
  97. IPN triangulation of GRB 240930B / EP 240930a
  98. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  99. EP240930a: Liverpool Telescope observations
  100. EP trigger ID 01709064214: GOTO confirms detection as a flare star

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