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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"

36348 results found.

  1. GRB 240912A: radio detection with the VLA
  2. Fermi GRB 241030A: Global MASTER-Net observations report
  3. GRB 241030A: AKO Optical Afterglow Detection
  4. Swift GRB 241030A: Global MASTER-Net observations report
  5. GRB 241030A: Swift/UVOT Detection
  6. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  7. GRB 241030A: SVOM/GRM observation
  8. GRB 241026A: Swift-BAT refined analysis
  9. GRB 241030A: SVOM/C-GFT optical observations
  10. GRB 241026A: LBT optical observations
  11. GRB 241030A: Multiband optical detection with Mephisto
  12. GRB 241030A: SVOM/VT optical afterglow observations
  13. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  14. GRB 241030A : MITSuME Akeno optical afterglow detection
  15. GRB 241030A: Enhanced Swift-XRT position
  16. GRB 241029A: GROWTH-India Telescope optical follow up
  17. GRB 241030A: TRT optical observations
  18. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  19. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  20. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  21. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  22. GRB 241030A: Fermi GBM Final Real-time Localization
  23. GRB 241029A: SAO RAS optical observations
  24. GRB 241026A: SAO RAS optical observations
  25. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  26. EP241021a: SAO RAS observations of rebrightening
  27. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  28. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  29. GRB 241026A: Swift/UVOT Upper Limits
  30. GRB 241029A: Swift-XRT observations
  31. GRB 241029A: Fermi GBM Observation
  32. GRB 241029A: AKO Optical Afterglow Detection
  33. GRB 241029A: GOTO optical afterglow detection
  34. GRB 241029A: MASTER early optical counterpart detection
  35. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  36. GRB 241029A: Mephisto observations
  37. EP 241026b: LBT possible optical counterpart (brightening source)
  38. GRB 241029A: TRT optical afterglow candidate detection
  39. GRB 241029A: Swift ToO observations
  40. GRB 241029A: SVOM/GRM observation
  41. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs
  42. GRB 241029A: Fermi GBM Final Real-time Localization
  43. GRB 240821A: Keck/LRIS spectroscopic observations
  44. GRB 241026A: the 100th GRB detected by GRBAlpha
  45. GRB 241026A: TNOT optical counterpart detection
  46. Konus-Wind detection of GRB 241025A
  47. GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
  48. GRB 241026A: LBT redshift confirmation
  49. GRB 241026A: GECAM detection
  50. GRB 241025A: further SAO RAS optical observations
  51. GRB 241026A: BTA and Zeiss-1000 optical observations
  52. GRB 241026A: SVOM/GRM observation
  53. GRB 241025A: Swift/UVOT Detection
  54. GRB 241026A: GROWTH-India Telescope optical observations
  55. GRB 241026A Fermi GBM Analysis
  56. GRB 241026A: BTA redshift identification of z = 2.79
  57. GRB 241026A: J-band observations with WINTER
  58. GRB 241025A: SAO RAS optical observations
  59. GRB 241026A: Las Cumbres optical detection
  60. GRB 241025A: Mondy optical observations
  61. EP241021a: further SAO RAS optical observations
  62. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  63. GRB 241026A: Swift-XRT refined Analysis
  64. GRB 241026A: Enhanced Swift-XRT position
  65. GRB 241026A: KAIT optical observations
  66. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  67. GRB 241026A: SAO RAS observations of possible optical afterglow
  68. Fermi GRB 241026A: Global MASTER-Net observations report
  69. GRB 241026A: Prompt enhanced Swift-XRT position
  70. GRB 241026A: Swift detection of a burst
  71. GRB 241026A: Fermi GBM Final Real-time Localization
  72. GRB241025A: 1.3m DFOT optical afterglow detection
  73. ​GRB 241025A: optical photometry from Konkoly
  74. GRB 241025A: GROWTH-India Telescope optical observations
  75. GRB 241025A: COLIBRÍ Detection of the Afterglow
  76. GRB 241025A: Swift-XRT refined Analysis
  77. GRB 241025C: Fermi GBM Detection
  78. GRB 241025A: Fermi GBM Observation
  79. IPN triangulation of GRB 241022A (short/hard)
  80. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  81. GRB 241025C: Fermi GBM Final Localization
  82. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  83. GRB 241025B: Fermi GBM Final Localization
  84. EP 241021a: Swift-XRT observations
  85. Fermi GRB 241025A: Global MASTER-Net observations report
  86. Swift GRB 241025A: Global MASTER-Net observations report
  87. EP241025a (GRB 241025A): EP observations update
  88. GRB 241025A : SVOM/VT optical afterglow observations
  89. GRB 241025A: Enhanced Swift-XRT position
  90. GRB 241001A: JWST spectroscopic identification of a supernova counterpart
  91. GRB 241025A: NOT spectroscopic redshift of z = 4.20
  92. GRB 241025A: DDOTI Afterglow detection
  93. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  94. GRB 241025A: SVOM/GRM observation
  95. GRB 241025A: TRT optical afterglow observation
  96. Fermi GRB 241024B: Global MASTER-Net observations report
  97. GRB 241025A: Fermi GBM Final Real-time Localization
  98. GRB 241025A: Swift detection of a burst with an optical counterpart
  99. GRB 241001A: ATCA radio observations
  100. GRB 241024B: Fermi GBM Final Localization

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