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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"

37525 results found.

  1. GRB 240929A : Leavitt Observatory optical upper limit
  2. Fermi GRB 240930B: Global MASTER-Net observations report
  3. GRB 240930B: Fermi GBM Final Real-time Localization
  4. IPN triangulation of GRB 240926A
  5. GRB 240825A: LBT optical observations
  6. GRB 240928A: SVOM/GRM observation
  7. Fermi GRB 240930A: Global MASTER-Net observations report
  8. Fermi Gamma-ray Burst Monitor trigger 749362078/240930172 (GRB 240930A) is not a GRB
  9. GRB 240930A: Fermi GBM Final Real-time Localization
  10. Fermi trigger No 749339671: Global MASTER-Net observations report
  11. Fermi Gamma-ray Burst Monitor trigger 749339671/240929913 is not a GRB
  12. GRB 240929A long GRB detected by INTEGRAL
  13. GRB 240929A: BALROG localization (Fermi Trigger 749332209 / GRB 240929826)
  14. Fermi GRB 240929A: Global MASTER-Net observations report
  15. GRB 240929A: Fermi GBM Final Real-time Localization
  16. IceCube-240929A - IceCube observation of a high-energy neutrino candidate track-like event
  17. Konus-Wind detection of GRB 240912A
  18. Swift Trigger 1256950 is probably not a GRB
  19. Fermi Gamma-ray Burst Monitor trigger 749191601/240928199 is not a GRB
  20. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  21. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  22. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  23. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  24. GRB 240926A: SVOM/GRM observation
  25. Konus-Wind detection of GRB 240905B
  26. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  27. EP240919a / GRB 240919A: SVOM/VT upper limit
  28. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  29. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  30. Konus-Wind detection of GRB 240918B
  31. IPN triangulation of GRB 240918B
  32. GRB 240905B: VZLUSAT-2 detection
  33. GRB 240918B: AstroSat CZTI detection
  34. EP240913A/GRB 240913C: AbAO optical upper limit
  35. EP240919a / GRB 240919A: Mondy optical upper limit
  36. EP240913a/GRB 240913C: 1.6m Mephisto observations
  37. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  38. EP240919a / GRB 240919A: REM optical and NIR upper limits
  39. EP240919a / GRB 240919A: KAIT optical upper limit
  40. GRB 240414A: further radio observations with the VLA
  41. GRB 240919A / EP240919a: SVOM/GRM observation
  42. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  43. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  44. GRB 240910A: radio detection with the VLA
  45. EP240919a: JinShan optical upper limits
  46. EP240919a is likely a GRB event (duplicate submission of 37563)
  47. EP240919a is likely a GRB event
  48. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  49. GRB 240918B: Fermi GBM Detection
  50. GRB 240910A: further Swift observations and confirmation of afterglow
  51. Fermi GRB 240918A: Global MASTER-Net observations report
  52. GRB 240918A: Fermi GBM Final Real-time Localization
  53. GRB 240916A: GRBAlpha detection
  54. GRB 240914B: GRBAlpha detection
  55. GRB 240916A: NOT optical observation
  56. GRB 240912A: Swift-BAT refined analysis
  57. IPN triangulation of GRB 240913C / EP 240913a
  58. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  59. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  60. GRB 240916A: Fermi GBM Observation
  61. GRB 240821A: radio observation with the VLA
  62. GRB 240916A (AT 2024vlp / GOTO24fzn): VLT/X-shooter redshift
  63. GRB 240916A: Swift-XRT afterglow detection
  64. GRB 240916A: Swift ToO observations
  65. GRB 240916A: JinShan optical decay in one of the two GOTO candidates
  66. GRB 240916B: Fermi GBM Final Real-time Localization
  67. GRB 240914B: Fermi GBM Final Localization
  68. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  69. GRB 240916A INTEGRAL SPI ACS LIGHT CURVE
  70. GRB 240916A: Fermi GBM Final Real-time Localization
  71. Fermi Gamma-ray Burst Monitor trigger 748124309/240915846 is not a GRB
  72. EP240913a/GRB 240913C: KAIT optical upper limit
  73. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  74. GRB 240913C: Fermi GBM detection
  75. GRB 240914A: Swift-XRT observations
  76. GRB 240913C: Joint location by ETJASMIN
  77. GRB 240914B: AstroSat CZTI detection
  78. EP240913A / GRB 240913C: AstroSat CZTI detection
  79. GRB 240914A: SVOM/GRM observation
  80. GRB 240910A: SVOM/VT optical observations
  81. GRB 240914A: Swift ToO observations
  82. EP240913a: ESO-NTT optical observations
  83. GRB 240914A: ESO-NTT optical observations
  84. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  85. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  86. GRB 240914A : An intermediate duration GRB located on-board by SVOM/ECLAIRs.
  87. GRB 240905E: further NOT optical observations
  88. EP240913a: A GRB Event
  89. GRB 240913B: Fermi GBM Final Real-time Localization
  90. GRB 240911A: LCO optical observations
  91. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  92. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  93. GRB 240912A: Swift/UVOT Detection
  94. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  95. Fermi trigger No 747920561: Global MASTER-Net observations report
  96. GRB 240912A: SVOM/GRM observation
  97. GRB 240911A: Swift-XRT observations
  98. Fermi GRB 240913A: Global MASTER-Net observations report
  99. GRB 240913A: Fermi GBM Final Real-time Localization
  100. GRB 240912A: J-band observations with WINTER

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