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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"

27251 results found.

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

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