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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"

27245 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 750792698/241016730 is not a GRB
  2. GRB 241017A : Detection of a weak and soft long duration GRB by SVOM/ECLAIRs
  3. Fermi GRB 241016B: Global MASTER-Net observations report
  4. GRB 241016B: Fermi GBM Final Localization
  5. Fermi GRB 241016A: Global MASTER-Net observations report
  6. GRB 241016A: Fermi GBM Final Real-time Localization
  7. IceCube Alert 241016.04: Global MASTER-Net observations report
  8. GRB 241010A: Swift-BAT refined analysis
  9. GRB 241013B: Fermi GBM Observation
  10. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  11. GRB 241013A: Fermi GBM Observation
  12. GRB241013A: REM observations
  13. GRB 241013B: SVOM/GRM observation
  14. Fermi GRB 241013B: Global MASTER-Net observations report
  15. Integral GRB241013.04: Global MASTER-Net observations report
  16. GRB 241013B: Fermi GBM Final Real-time Localization
  17. GRB 241013A: Fermi GBM Final Real-time Localization
  18. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  19. GRB 241011A: Fermi GBM Final Real-time Localization
  20. GRB 241009A: GRANDMA optical upper limits
  21. GRB 241010A: JinShan optical observations and potential host galaxy
  22. GRB 241010A: Swift-XRT refined Analysis
  23. Fermi trigger No 750211959: Global MASTER-Net observations report
  24. Fermi Gamma-ray Burst Monitor trigger 750303285/241011066 is not a GRB
  25. Fermi Gamma-ray Burst Monitor trigger 750291012/241010924 is not a GRB
  26. Swift GRB 241010A: Global MASTER-Net observations report
  27. Fermi trigger No 750291012: Global MASTER-Net observations report
  28. Fermi GRB 241010B: Global MASTER-Net observations report
  29. GRB 241010B: Fermi GBM Final Real-time Localization
  30. GRB 241010A: LCO optical observations
  31. GRB 241010A: Swift detection of a burst with an optical counterpart
  32. GRB 241006A: Swift-BAT refined analysis
  33. GRB 241009A : Detection of a long duration GRB by SVOM/ECLAIRs
  34. GRB 241008A: Fermi GBM Observation
  35. GRB 241008A: Fermi-LAT detection
  36. GRB 241002A: NOT optical upper limits
  37. Fermi GRB 241008A: Global MASTER-Net observations report
  38. GRB 241008A: BALROG localization (Fermi Trigger 750117609 / GRB 241008917)
  39. GRB 241008A: Fermi GBM Final Real-time Localization
  40. GRB 241006A: GRANDMA optical upper limits
  41. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  42. GRB 241006A: Swift-XRT refined Analysis
  43. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  44. GRB 241006A: Swift/UVOT Upper Limits
  45. GRB 241006A: SVOM/VT follow-up and optical upper limit
  46. IceCube Alert 241006.94: Global MASTER-Net observations report
  47. GRB 241006A: Swift detection of a burst
  48. Swift GRB241006.91: Global MASTER-Net observations report
  49. GRB 240930B: SVOM/C-GFT optical upper limit
  50. LIGO/Virgo/KAGRA S241005bo: Retraction of GW compact binary merger candidate
  51. Fermi trigger No 749721670: Global MASTER-Net observations report
  52. GRB 241004A: SVOM/GRM observation
  53. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  54. GRB 240930B / EP 240930a: SVOM/GRM observation
  55. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  56. GRB 241002B: Fermi GBM Observation
  57. Fermi trigger No 749735279: Global MASTER-Net observations report
  58. Fermi trigger No 749630753: Global MASTER-Net observations report
  59. Fermi trigger No 749693019: Global MASTER-Net observations report
  60. GRB 241002C: SVOM/C-GFT optical upper limit
  61. GRB 241002A: Swift-BAT refined analysis
  62. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  63. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  64. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  65. IPN triangulation of GRB 240930B / EP 240930a
  66. GRB 241001A : SVOM/VT optical detection
  67. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  68. GRB 241002D: SVOM/GRM observation
  69. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  70. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  71. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  72. GRB 241002C : MITSuME Akeno optical upper limits
  73. GRB241001A: REM optical/NIR upper limits
  74. GRB 241002A: Swift/UVOT Upper Limits
  75. EP240930a: Liverpool Telescope observations
  76. GRB 241002A: Swift-XRT refined Analysis
  77. GRB 241002A: LCOGT Optical Upper Limits
  78. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  79. GRB 241001A: Swift/UVOT Detection
  80. GRB 241002B: GOTO optical counterpart candidate
  81. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  82. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  83. GRB 240929A: Liverpool Telescope prompt followup observations
  84. Fermi GRB 241002B: Global MASTER-Net observations report
  85. EP trigger ID 01709064214: the X-ray transient is most likely a stellar flare event
  86. GRB 241002B: Fermi GBM Final Real-time Localization
  87. GRB241001A: optical afterglow candidate
  88. GRB 241001A: BOOTES-6/DPRT optical upper limit
  89. GRB 241002A: Swift detection of a burst
  90. GRB 240930B: Fermi GBM Observation
  91. EP240930a : KAIT optical upper limit
  92. GRB 241001A : Detection of a soft transient by ECLAIRs onboard SVOM
  93. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  94. EP240930a: EP-FXT follow-up observation update
  95. EP240930a: GOTO optical upper limits
  96. GRB 240929A: SVOM/GRM observation
  97. EP EP240930a: Global MASTER-Net observations report
  98. EP240930a: EP-WXT detection of a fast X-ray transient
  99. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  100. LIGO/Virgo/KAGRA S240930df: 1 counterpart neutrino candidate event from an IceCube neutrino search

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