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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"

28201 results found.

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

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