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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"

28205 results found.

  1. IPN triangulation of GRB 240930B / EP 240930a
  2. GRB 241001A : SVOM/VT optical detection
  3. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  4. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  5. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  6. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  7. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  8. GRB241001A: REM optical/NIR upper limits
  9. GRB 241002A: Swift/UVOT Upper Limits
  10. GRB 241002A: Swift-XRT refined Analysis
  11. GRB 241002A: LCOGT Optical Upper Limits
  12. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  13. GRB 241001A: Swift/UVOT Detection
  14. GRB 241001A: VLT/X-shooter redshift
  15. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  16. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  17. GRB 241001A: correction to GCN 37667
  18. GRB 241001A: Swift-XRT observations
  19. EP trigger ID 01709064214: the X-ray transient is most likely a stellar flare event
  20. GRB 241002B: Fermi GBM Final Real-time Localization
  21. GRB241001A: optical afterglow candidate
  22. GRB 241002A: 1.5m OSN optical upper limit
  23. GRB 241002A: Enhanced Swift-XRT position
  24. GRB 241001A: BOOTES-6/DPRT optical upper limit
  25. GRB 241002A: Swift detection of a burst
  26. GRB 241001A: Swift ToO observations
  27. GRB 240930B: GRBAlpha detection
  28. GRB 240929A: GRBAlpha detection
  29. GRB 241001A : Detection of a soft transient by ECLAIRs onboard SVOM
  30. EP240930a: EP-FXT follow-up observation update
  31. EP240930a: EP-WXT detection of a fast X-ray transient
  32. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  33. AMON NuEM 240926A: Swift XRT Follow-up
  34. GRB 240930B: Fermi GBM Final Real-time Localization
  35. IPN triangulation of GRB 240926A
  36. GRB 240930A: Fermi GBM Final Real-time Localization
  37. GRB 240929A: Fermi GBM Final Real-time Localization
  38. IceCube-240929A - IceCube observation of a high-energy neutrino candidate track-like event
  39. Konus-Wind detection of GRB 240912A
  40. Swift Trigger 1256950 is probably not a GRB
  41. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  42. Konus-Wind detection of GRB 240905B
  43. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  44. EP240918b and EP240918c: EP-FXT follow-up observations
  45. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  46. Konus-Wind detection of GRB 240918B
  47. IPN triangulation of GRB 240918B
  48. GRB 240905B: VZLUSAT-2 detection
  49. LIGO/Virgo S240919bn: GOTO optical upper limits
  50. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  51. GRB 240918B: AstroSat CZTI detection
  52. EP240919a: EP-FXT follow-up observation update
  53. EP240913A/GRB 240913C: AbAO optical upper limit
  54. EP240913a/GRB 240913C: 1.6m Mephisto observations
  55. EP240918a: SVOM/VT upper limit
  56. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  57. EP240918b and EP240918c: Optical upper limits with Kinder observations
  58. EP240919a: Optical upper limit with Kinder observations
  59. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  60. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  61. GRB 240910A: radio detection with the VLA
  62. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  63. EP240919a: GOTO optical upper limits
  64. EP240919a: EP-WXT detection of a fast X-ray transient
  65. GRB 240918B: Fermi GBM Detection
  66. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  67. EP240918a: EP observation update
  68. GRB 240910A: further Swift observations and confirmation of afterglow
  69. EP240918a: Swift-XRT observation
  70. GRB 240918A: Fermi GBM Final Real-time Localization
  71. EP240918a: YAHPT Optical Upper Limit
  72. GRB 240916A: GRBAlpha detection
  73. GRB 240914B: GRBAlpha detection
  74. EP240918a: an X-ray transient detected by Einstein Probe
  75. GRB 240916A: NOT optical observation
  76. GRB 240912A: Swift-BAT refined analysis
  77. IPN triangulation of GRB 240913C / EP 240913a
  78. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  79. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  80. GRB 240916A: Fermi GBM Observation
  81. GRB 240916A (AT 2024vlp / GOTO24fzn): VLT/X-shooter redshift
  82. GRB 240916A: Swift-XRT afterglow detection
  83. GRB 240916A: Swift ToO observations
  84. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  85. GRB 240916B: Fermi GBM Final Real-time Localization
  86. GRB 240914B: Fermi GBM Final Localization
  87. GRB 240916A: Fermi GBM Final Real-time Localization
  88. EP240913a/GRB 240913C: KAIT optical upper limit
  89. GRB 240913C: Fermi GBM detection
  90. GRB 240914A: Swift-XRT observations
  91. GRB 240914B: AstroSat CZTI detection
  92. EP240913A / GRB 240913C: AstroSat CZTI detection
  93. GRB 240910A: SVOM/VT optical observations
  94. GRB 240914A: Swift ToO observations
  95. EP240913a: ESO-NTT optical observations
  96. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  97. GRB 240905E: further NOT optical observations
  98. EP240913a: EP-WXT detection of a fast X-ray transient
  99. GRB 240913B: Fermi GBM Final Real-time Localization
  100. GRB 240911A: LCO optical observations

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