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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"

36400 results found.

  1. GRB 241029A: GRBAlpha detection
  2. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  3. Swift GRB 241101A: Global MASTER-Net observations report
  4. GRB 241101A: FRAM-ORM optical limit
  5. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  6. EP241021a: Upper limit from Konus-Wind observations
  7. GRB 241101A: Swift-BAT refined analysis
  8. GRB 241030A: further SAO RAS optical observations
  9. GRB 241030A: Optical Observations via Virtual Telescope Project
  10. GRB 241030B: Swift-XRT refined Analysis
  11. GRB 241026A: SAO RAS optical observations
  12. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  13. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  14. GRB 241101A: Swift detection of a burst
  15. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  16. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  17. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  18. GRB 241030B: Montarrenti Observatory optical upper limit
  19. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  20. GRB 241030A: SAO RAS optical observations
  21. GRB 241030A: Fermi GBM Observation
  22. GRB 241030B : GIT optical upper limits
  23. GRB 241030B: LCOGT Optical Upper Limits
  24. GRB 241030B: Swift-BAT refined analysis
  25. GRB 241030A: Swift-BAT refined analysis
  26. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  27. GRB 241030B: Swift/UVOT Detection
  28. GRB 241029A: LCO optical detection
  29. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  30. GRB 241030B: SVOM/GRM observation
  31. GRB 241030B : MITSuME Akeno optical upper limits
  32. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  33. GRB 241030B: SVOM/VT optical afterglow observations
  34. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  35. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  36. GRB241030B: Fermi GBM Observation
  37. GRB 241030B: BTA observations
  38. GRB 241029A: SVOM/VT optical afterglow observations
  39. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  40. GRB 241030B: Enhanced Swift-XRT position
  41. GRB 241030B: optical observations from the INAF Asiago Observatory
  42. GRB241030B: GRANDMA/TAROT Upper Limit
  43. GRB 241030A: Swift-XRT refined Analysis
  44. GRB 241030B: SAO RAS optical observations
  45. GRB 241030B: AKO Optical Afterglow Detection
  46. GRB 241030B: Nanshan/HMT optical afterglow detection
  47. GRB 241030B: SVOM/ECLAIRs detection of a burst
  48. GRB 241030B: Prompt enhanced Swift-XRT position
  49. Konus-Wind detection of GRB 241030A
  50. GRB 241030B: Swift detection of a burst
  51. GRB 241030B: Fermi GBM Final Real-time Localization
  52. GRB 241030A: Fermi-LAT detection
  53. GRB 240912A: radio detection with the VLA
  54. Fermi GRB 241030A: Global MASTER-Net observations report
  55. GRB 241030A: AKO Optical Afterglow Detection
  56. Swift GRB 241030A: Global MASTER-Net observations report
  57. GRB 241030A: Swift/UVOT Detection
  58. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  59. GRB 241030A: SVOM/GRM observation
  60. GRB 241026A: Swift-BAT refined analysis
  61. GRB 241030A: SVOM/C-GFT optical observations
  62. GRB 241026A: LBT optical observations
  63. GRB 241030A: Multiband optical detection with Mephisto
  64. GRB 241030A: SVOM/VT optical afterglow observations
  65. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  66. GRB 241030A : MITSuME Akeno optical afterglow detection
  67. GRB 241030A: Enhanced Swift-XRT position
  68. GRB 241029A: GROWTH-India Telescope optical follow up
  69. GRB 241030A: TRT optical observations
  70. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  71. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  72. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  73. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  74. GRB 241030A: Fermi GBM Final Real-time Localization
  75. GRB 241029A: SAO RAS optical observations
  76. GRB 241026A: SAO RAS optical observations
  77. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  78. EP241021a: SAO RAS observations of rebrightening
  79. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  80. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  81. GRB 241026A: Swift/UVOT Upper Limits
  82. GRB 241029A: Swift-XRT observations
  83. GRB 241029A: Fermi GBM Observation
  84. GRB 241029A: AKO Optical Afterglow Detection
  85. GRB 241029A: GOTO optical afterglow detection
  86. GRB 241029A: MASTER early optical counterpart detection
  87. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  88. GRB 241029A: Mephisto observations
  89. EP 241026b: LBT possible optical counterpart (brightening source)
  90. GRB 241029A: TRT optical afterglow candidate detection
  91. GRB 241029A: Swift ToO observations
  92. GRB 241029A: SVOM/GRM observation
  93. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs
  94. GRB 241029A: Fermi GBM Final Real-time Localization
  95. GRB 240821A: Keck/LRIS spectroscopic observations
  96. GRB 241026A: the 100th GRB detected by GRBAlpha
  97. GRB 241026A: TNOT optical counterpart detection
  98. Konus-Wind detection of GRB 241025A
  99. GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
  100. GRB 241026A: LBT redshift confirmation

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