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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"

27250 results found.

  1. GRB 240929A: SVOM/GRM observation
  2. EP EP240930a: Global MASTER-Net observations report
  3. EP240930a: EP-WXT detection of a fast X-ray transient
  4. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  5. LIGO/Virgo/KAGRA S240930df: 1 counterpart neutrino candidate event from an IceCube neutrino search
  6. GRB 240929A : Leavitt Observatory optical upper limit
  7. Fermi GRB 240930B: Global MASTER-Net observations report
  8. GRB 240930B: Fermi GBM Final Real-time Localization
  9. GRB 240928A: SVOM/GRM observation
  10. Fermi GRB 240930A: Global MASTER-Net observations report
  11. Fermi Gamma-ray Burst Monitor trigger 749362078/240930172 (GRB 240930A) is not a GRB
  12. GRB 240930A: Fermi GBM Final Real-time Localization
  13. Fermi trigger No 749339671: Global MASTER-Net observations report
  14. Fermi Gamma-ray Burst Monitor trigger 749339671/240929913 is not a GRB
  15. GRB 240929A: BALROG localization (Fermi Trigger 749332209 / GRB 240929826)
  16. Fermi GRB 240929A: Global MASTER-Net observations report
  17. GRB 240929A: Fermi GBM Final Real-time Localization
  18. Integral GRB240929.83: Global MASTER-Net observations report
  19. Swift Trigger 1256950 is probably not a GRB
  20. Fermi Gamma-ray Burst Monitor trigger 749191601/240928199 is not a GRB
  21. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  22. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  23. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  24. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  25. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  26. GRB 240926A: SVOM/GRM observation
  27. EP trigger ID 01709061302: the X-ray transient is likely a stellar flare event
  28. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  29. EP240919a / GRB 240919A: SVOM/VT upper limit
  30. EP240918b and EP240918c: EP-FXT follow-up observations
  31. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  32. EP trigger ID 01709059262: correction to the observation start time and source localization
  33. EP trigger ID 01709059262: the X-ray transient is likely a stellar flare event
  34. LIGO/Virgo S240919bn: GOTO optical upper limits
  35. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  36. EP240919a: EP-FXT follow-up observation update
  37. EP240918a: SVOM/VT upper limit
  38. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  39. EP240919a / GRB 240919A: REM optical and NIR upper limits
  40. EP240919a / GRB 240919A: KAIT optical upper limit
  41. GRB 240919A / EP240919a: SVOM/GRM observation
  42. EP EP240919a: Global MASTER-Net observations report
  43. EP240919a: NOT and Gemini optical observations
  44. EP240919a: JinShan optical upper limits
  45. EP240919a: EP-WXT detection of a fast X-ray transient
  46. GRB 240918B: Fermi GBM Detection
  47. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  48. EP240918a: EP observation update
  49. EP240918a: Swift-XRT observation
  50. Fermi GRB 240918A: Global MASTER-Net observations report
  51. GRB 240918A: Fermi GBM Final Real-time Localization
  52. EP EP240918a: Global MASTER-Net observations report
  53. EP240918a: JinShan optical upper limits
  54. EP240918a: Optical upper limits with Kinder observations
  55. EP240918a: GMG Optical Upper Limit
  56. GRB 240914B: GRBAlpha detection
  57. EP240918a: an X-ray transient detected by Einstein Probe
  58. GRB 240916A: NOT optical observation
  59. GRB 240912A: Swift-BAT refined analysis
  60. IPN triangulation of GRB 240913C / EP 240913a
  61. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  62. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  63. GRB 240916A: Fermi GBM Observation
  64. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  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. The EP-WXT triggers 01709047257 and 01709047278 are not real sources
  69. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  70. EP EP240913a: Global MASTER-Net observations report
  71. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  72. GRB 240916A: Fermi GBM Final Real-time Localization
  73. Fermi Gamma-ray Burst Monitor trigger 748124309/240915846 is not a GRB
  74. EP240913a: VLT/HAWK-I near-infrared upper limits
  75. EP240913a/GRB 240913C: KAIT optical upper limit
  76. GRB 240913C: Fermi GBM detection
  77. GRB 240914B: AstroSat CZTI detection
  78. GRB 240914A: SVOM/GRM observation
  79. GRB 240910A: SVOM/VT optical observations
  80. EP240913a: NOT optical upper limits
  81. EP240913a: JinShan optical upper limits
  82. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  83. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  84. GRB 240914A : An intermediate duration GRB located on-board by SVOM/ECLAIRs.
  85. GRB 240905E: further NOT optical observations
  86. EP240913a: A GRB Event
  87. EP240913a: EP-WXT detection of a fast X-ray transient
  88. GRB 240913B: Fermi GBM Final Real-time Localization
  89. GRB 240911A: LCO optical observations
  90. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  91. Fermi Gamma-ray Burst Monitor trigger 747837485/240912526 is not a GRB
  92. GRB 240912A: Swift/UVOT Detection
  93. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  94. Fermi trigger No 747920561: Global MASTER-Net observations report
  95. GRB 240912A: SVOM/GRM observation
  96. Fermi GRB 240913A: Global MASTER-Net observations report
  97. GRB 240913A: Fermi GBM Final Real-time Localization
  98. GRB 240912A: Swift-XRT refined Analysis
  99. GRB 240912A: Fermi GBM Observation
  100. Swift GRB 240912A: Global MASTER-Net observations report

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