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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"

45754 results found.

  1. GRB 241030B: SVOM/ECLAIRs detection of a burst
  2. GRB 241030B: Prompt enhanced Swift-XRT position
  3. Konus-Wind detection of GRB 241030A
  4. GRB 241030B: Swift detection of a burst
  5. GRB 241030B: Fermi GBM Final Real-time Localization
  6. GRB 241030A: Fermi-LAT detection
  7. GRB 240912A: radio detection with the VLA
  8. Fermi GRB 241030A: Global MASTER-Net observations report
  9. GRB 241030A: AKO Optical Afterglow Detection
  10. Swift GRB 241030A: Global MASTER-Net observations report
  11. GRB 241030A: Swift/UVOT Detection
  12. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  13. GRB 241030A: SVOM/GRM observation
  14. GRB 241026A: Swift-BAT refined analysis
  15. GRB 241030A: SVOM/C-GFT optical observations
  16. GRB 241026A: LBT optical observations
  17. EP241021a: Optical rebrightening observations with Mephisto
  18. EP241026b: EP-FXT follow-up observation
  19. GRB 241030A: Multiband optical detection with Mephisto
  20. GRB 241030A: SVOM/VT optical afterglow observations
  21. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  22. GRB 241030A : MITSuME Akeno optical afterglow detection
  23. GRB 241030A: Enhanced Swift-XRT position
  24. GRB 241029A: GROWTH-India Telescope optical follow up
  25. GRB 241030A: TRT optical observations
  26. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  27. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  28. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  29. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  30. GRB 241030A: Fermi GBM Final Real-time Localization
  31. GRB 241029A: SAO RAS optical observations
  32. GRB 241026A: SAO RAS optical observations
  33. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  34. EP241021a: SAO RAS observations of rebrightening
  35. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  36. EP241021a: ATCA radio observations
  37. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  38. GRB 241026A: Swift/UVOT Upper Limits
  39. GRB 241029A: Swift-XRT observations
  40. GRB 241029A: Fermi GBM Observation
  41. GRB 241029A: AKO Optical Afterglow Detection
  42. GRB 241029A: GOTO optical afterglow detection
  43. EP241021a: continued SOAR observations confirm optical rebrightening
  44. GRB 241029A: MASTER early optical counterpart detection
  45. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  46. GRB 241029A: Mephisto observations
  47. EP 241026b: LBT possible optical counterpart (brightening source)
  48. GRB 241029A: TRT optical afterglow candidate detection
  49. GRB 241029A: Swift ToO observations
  50. GRB 241029A: SVOM/GRM observation
  51. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs
  52. Fermi trigger No 751861204: Global MASTER-Net observations report
  53. GRB 241029A: Fermi GBM Final Real-time Localization
  54. GRB 240821A: Keck/LRIS spectroscopic observations
  55. EP241021a: Gemini-South detection of optical rebrightening
  56. GRB 241026A: the 100th GRB detected by GRBAlpha
  57. GRB 241026A: TNOT optical counterpart detection
  58. Konus-Wind detection of GRB 241025A
  59. GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
  60. GRB 241026A: LBT redshift confirmation
  61. GRB 241026A: GECAM detection
  62. GRB 241025A: further SAO RAS optical observations
  63. GRB 241026A: BTA and Zeiss-1000 optical observations
  64. GRB 241026A: SVOM/GRM observation
  65. EP241026B: GROWTH-India Telescope optical upper limit
  66. GRB 241025A: Swift/UVOT Detection
  67. GRB 241026A: GROWTH-India Telescope optical observations
  68. GRB 241026A Fermi GBM Analysis
  69. GRB 241026A: BTA redshift identification of z = 2.79
  70. GRB 241026A: J-band observations with WINTER
  71. GRB 241025A: SAO RAS optical observations
  72. GRB 241026A: Las Cumbres optical detection
  73. GRB 241025A: Mondy optical observations
  74. EP241021a: SOAR observations of the optical counterpart
  75. EP241021a: further SAO RAS optical observations
  76. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  77. GRB 241026A: Swift-XRT refined Analysis
  78. EP 241026b: LBT optical observations
  79. EP241021a: e-MERLIN radio observation
  80. EP EP241026b: Global MASTER-Net observations report
  81. GRB 241026A: Enhanced Swift-XRT position
  82. GRB 241026A: KAIT optical observations
  83. EP241026b: EP detection of a fast X-ray transient
  84. Fermi trigger No 751616906: Global MASTER-Net observations report
  85. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  86. GRB 241026A: SAO RAS observations of possible optical afterglow
  87. Fermi GRB 241026A: Global MASTER-Net observations report
  88. GRB 241026A: Prompt enhanced Swift-XRT position
  89. GRB 241026A: Swift detection of a burst
  90. Swift GRB241026.95: Global MASTER-Net observations report
  91. GRB 241026A: Fermi GBM Final Real-time Localization
  92. GRB241025A: 1.3m DFOT optical afterglow detection
  93. EP241021a: optical follow-up observations with Xinglong Observatory
  94. ​GRB 241025A: optical photometry from Konkoly
  95. GRB 241025A: GROWTH-India Telescope optical observations
  96. GRB 241025A: COLIBRÍ Detection of the Afterglow
  97. GRB 241025A: Swift-XRT refined Analysis
  98. GRB 241025C: Fermi GBM Detection
  99. GRB 241025A: Fermi GBM Observation
  100. IPN triangulation of GRB 241022A (short/hard)

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