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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.

Advanced Search Examples (click to copy):

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

35333 results found.

  1. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  2. GRB 241105A: BOOTES-7 optical detection
  3. GRB 241030A: Mondy optical observations
  4. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  5. Konus-Wind detection of GRB 241105A (short with extended emission)
  6. Konus-Wind detection of GRB 241021A
  7. GRB 241105A: SVOM/VT optical afterglow observations
  8. GRB 241105A: Swift-XRT afterglow detection
  9. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  10. GRB 241104A: Swift-XRT observations
  11. GRB 240511A: LCO upper limits
  12. GRB 241104A: Fermi GBM Observation
  13. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  14. GRB 241105A: Swift ToO observations
  15. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  16. GRB 241104A: Swift ToO observations
  17. GRB 241104A: NOT optical non-detection
  18. GRB 241105A: GOTO tentative optical counterpart candidate
  19. Fermi GRB 241105A: Global MASTER-Net observations report
  20. GRB 241104A: SVOM/VT optical candidate
  21. GRB 241105A: Fermi GBM Final Real-time Localization
  22. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  23. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  24. GRB 241104A: SVOM/GRM observation
  25. EP241104a: EP detection of GRB 241104A X-ray emission
  26. GRB 241010A: host galaxy redshift z = 0.977
  27. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  28. GRB 240821A: further radio observations with the VLA
  29. Fermi GRB 241104A: Global MASTER-Net observations report
  30. GRB 241104A: Fermi GBM Final Real-time Localization
  31. GRB 241030A: GRBAlpha detection
  32. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  33. GRB 241030A: Rapid release of TESS data.
  34. GRB 241029A: GRBAlpha detection
  35. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  36. Swift GRB 241101A: Global MASTER-Net observations report
  37. GRB 241101A: FRAM-ORM optical limit
  38. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  39. EP241021a: Upper limit from Konus-Wind observations
  40. GRB 241101A: Swift-BAT refined analysis
  41. GRB 241030A: further SAO RAS optical observations
  42. GRB 241030A: Optical Observations via Virtual Telescope Project
  43. GRB 241030B: Swift-XRT refined Analysis
  44. GRB 241026A: SAO RAS optical observations
  45. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  46. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  47. GRB 241101A: Swift detection of a burst
  48. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  49. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  50. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  51. GRB 241030B: Montarrenti Observatory optical upper limit
  52. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  53. GRB 241030A: SAO RAS optical observations
  54. GRB 241030A: Fermi GBM Observation
  55. GRB 241030B : GIT optical upper limits
  56. GRB 241030B: LCOGT Optical Upper Limits
  57. GRB 241030B: Swift-BAT refined analysis
  58. GRB 241030A: Swift-BAT refined analysis
  59. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  60. GRB 241030B: Swift/UVOT Detection
  61. GRB 241029A: LCO optical detection
  62. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  63. GRB 241030B: SVOM/GRM observation
  64. GRB 241030B : MITSuME Akeno optical upper limits
  65. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  66. GRB 241030B: SVOM/VT optical afterglow observations
  67. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  68. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  69. GRB241030B: Fermi GBM Observation
  70. GRB 241030B: BTA observations
  71. GRB 241029A: SVOM/VT optical afterglow observations
  72. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  73. GRB 241030B: Enhanced Swift-XRT position
  74. GRB 241030B: optical observations from the INAF Asiago Observatory
  75. GRB241030B: GRANDMA/TAROT Upper Limit
  76. GRB 241030A: Swift-XRT refined Analysis
  77. GRB 241030B: SAO RAS optical observations
  78. GRB 241030B: AKO Optical Afterglow Detection
  79. GRB 241030B: Nanshan/HMT optical afterglow detection
  80. GRB 241030B: SVOM/ECLAIRs detection of a burst
  81. GRB 241030B: Prompt enhanced Swift-XRT position
  82. Konus-Wind detection of GRB 241030A
  83. GRB 241030B: Swift detection of a burst
  84. GRB 241030B: Fermi GBM Final Real-time Localization
  85. GRB 241030A: Fermi-LAT detection
  86. GRB 240912A: radio detection with the VLA
  87. Fermi GRB 241030A: Global MASTER-Net observations report
  88. GRB 241030A: AKO Optical Afterglow Detection
  89. Swift GRB 241030A: Global MASTER-Net observations report
  90. GRB 241030A: Swift/UVOT Detection
  91. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  92. GRB 241030A: SVOM/GRM observation
  93. GRB 241026A: Swift-BAT refined analysis
  94. GRB 241030A: SVOM/C-GFT optical observations
  95. GRB 241026A: LBT optical observations
  96. GRB 241030A: Multiband optical detection with Mephisto
  97. GRB 241030A: SVOM/VT optical afterglow observations
  98. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  99. GRB 241030A : MITSuME Akeno optical afterglow detection
  100. GRB 241030A: Enhanced Swift-XRT position

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