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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"

45757 results found.

  1. GRB 241025C: Fermi GBM Detection
  2. GRB 241025A: Fermi GBM Observation
  3. IPN triangulation of GRB 241022A (short/hard)
  4. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  5. GRB 241025C: Fermi GBM Final Localization
  6. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  7. GRB 241025B: Fermi GBM Final Localization
  8. Fermi trigger No 751563375: Global MASTER-Net observations report
  9. Fermi trigger No 751554401: Global MASTER-Net observations report
  10. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  11. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  12. EP 241021a: Swift-XRT observations
  13. EP241021a: optical follow-up observations with the Liverpool Telescope
  14. Fermi GRB 241025A: Global MASTER-Net observations report
  15. Swift GRB 241025A: Global MASTER-Net observations report
  16. EP241025a (GRB 241025A): EP observations update
  17. GRB 241025A : SVOM/VT optical afterglow observations
  18. EP 241021A: Swift ToO observations
  19. EP241021a: Liverpool Telescope optical follow-up observations
  20. GRB 241025A: Enhanced Swift-XRT position
  21. GRB 241001A: JWST spectroscopic identification of a supernova counterpart
  22. GRB 241025A: NOT spectroscopic redshift of z = 4.20
  23. GRB 241025A: DDOTI Afterglow detection
  24. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  25. GRB 241025A: SVOM/GRM observation
  26. GRB 241025A: TRT optical afterglow observation
  27. Fermi GRB 241024B: Global MASTER-Net observations report
  28. GRB 241025A: Fermi GBM Final Real-time Localization
  29. GRB 241025A: Swift detection of a burst with an optical counterpart
  30. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  31. GRB 241001A: ATCA radio observations
  32. GRB 241024B: Fermi GBM Final Localization
  33. EP241021a: No Detection in Fermi-GBM Observation
  34. GRB 241010A: VIRT Optical Upper Limit
  35. GRB 241024A: Fermi GBM Final Localisation
  36. EP241021a: VLT/FORS2 redshift z = 0.75
  37. Fermi trigger No 751449953: Global MASTER-Net observations report
  38. EP241021a: SAO RAS optical observations
  39. EP241021a: KAIT optical observations
  40. EP241021a: EP-FXT follow-up observation update
  41. IPN triangulation of GRB 241021A (long)
  42. EP241021a: Optical counterpart observations with the Liverpool Telescope
  43. EP241021a: 1.3m DFOT Optical observations
  44. EP241021a: GSP detects optical candidate counterpart
  45. EP241021a: Optical upper limits with Kinder observations
  46. EP241021a: TRT optical observations
  47. GRB 241018A: SVOM/C-GFT optical observations
  48. EP241021a: NOT likely optical counterpart
  49. EP EP241021a: Global MASTER-Net observations report
  50. GRB241017A: 1.3m DFOT optical upper limit
  51. GRB 241018A: 1.3m DFOT Optical upper limit
  52. GRB 241018A: EP-FXT afterglow detection
  53. EP241021a: GOTO optical upper limits
  54. EP241021a: EP detection of a fast X-ray transient
  55. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  56. Konus-Wind detection of GRB 241018A
  57. GRB 241018A: SVOM/GRM observation
  58. GRB 241018A/sb24101802: Mephisto optical upper limit
  59. GRB 241017A/sb24101702: Mephisto optical upper limit
  60. GRB 241018A: BOOTES-4/MET optical upper limit
  61. GRB 241018A: Mondy optical upper limit
  62. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  63. GRB 241018A: GROWTH-India telescope optical upper limit
  64. GRB241018A: XingLong Optical Upper Limit
  65. GRB 241018A: Swift-XRT observations
  66. GRB 241018A: REM optical/NIR upper limits
  67. GRB 241018A: NOT optical observations
  68. GRB 241017A: SVOM/VT follow-up and optical upper limit
  69. GRB 241018A: SVOM/VT follow-up and optical candidate
  70. GRB 241018A: LCO/0.4m optical upper limits
  71. GRB 241018A: Swift ToO observations
  72. GRB 241006A: VIRT Optical Upper Limit
  73. GRB 240727A: VIRT Optical Upper Limit
  74. GRB 241018A: X-ray afterglow candidate observed by MXT
  75. GRB 241016B: Fermi GBM Observations
  76. GRB 241018A: Detection of a bright long GRB by SVOM
  77. GRB 241017A: Swift-XRT observations
  78. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  79. GRB 241001A: EP-FXT afterglow detection
  80. GRB 241017A: GROWTH-India Telescope optical upper limit
  81. GRB241017A: TOO Observations by SVOM/MXT
  82. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  83. GRB 241017A: J-band upper limit from WINTER
  84. Fermi trigger No 750788395: Global MASTER-Net observations report
  85. GRB 241016B: SVOM/GRM observation
  86. GRB241016C: Fermi GBM Final Localization
  87. Fermi Gamma-ray Burst Monitor trigger 750792698/241016730 is not a GRB
  88. GRB 241017A: Swift ToO observations
  89. GRB 241017A : Detection of a weak and soft long duration GRB by SVOM/ECLAIRs
  90. Fermi GRB 241016B: Global MASTER-Net observations report
  91. GRB 241016B: Fermi GBM Final Localization
  92. Fermi GRB 241016A: Global MASTER-Net observations report
  93. GRB 241016A: Fermi GBM Final Real-time Localization
  94. IceCube alert 139977_2910365 retraction
  95. IceCube Alert 241016.04: Global MASTER-Net observations report
  96. GRB 241010A: Swift-BAT refined analysis
  97. GRB 241013B: Fermi GBM Observation
  98. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  99. GRB 241013A: Fermi GBM Observation
  100. GRB 240916A: radio detection with the VLA

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