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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"

36346 results found.

  1. GRB 241002B: Fermi GBM Observation
  2. GRB 241002B: Swift-XRT observations
  3. GRB 241002C: SVOM/C-GFT optical upper limit
  4. GRB 241002A: Swift-BAT refined analysis
  5. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  6. GRB 241002B: Swift ToO observations
  7. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  8. Konus-Wind detection of GRB 240926A
  9. GRB 241002B: PRIME near-infrared detection
  10. GRB 241002C: Swift ToO observations
  11. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  12. IPN triangulation of GRB 240930B / EP 240930a
  13. GRB 241001A : SVOM/VT optical detection
  14. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  15. GRB 241002D: SVOM/GRM observation
  16. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  17. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  18. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  19. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  20. GRB 241002C : MITSuME Akeno optical upper limits
  21. LIGO/Virgo/KAGRA S240925n: Updated Sky localization
  22. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  23. GRB241001A: REM optical/NIR upper limits
  24. GRB 241002A: Swift/UVOT Upper Limits
  25. GRB 241002A: Swift-XRT refined Analysis
  26. GRB 241002A: LCOGT Optical Upper Limits
  27. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  28. GRB 241001A: Swift/UVOT Detection
  29. GRB 241001A: VLT/X-shooter redshift
  30. GRB 241002B: GOTO optical counterpart candidate
  31. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  32. GRB 241001A: correction to GCN 37667
  33. GRB 240929A: Liverpool Telescope prompt followup observations
  34. Fermi GRB 241002B: Global MASTER-Net observations report
  35. GRB 241001A: Swift-XRT observations
  36. GRB 241002B: Fermi GBM Final Real-time Localization
  37. GRB241001A: optical afterglow candidate
  38. GRB 241002A: 1.5m OSN optical upper limit
  39. GRB 241002A: Enhanced Swift-XRT position
  40. GRB 241001A: BOOTES-6/DPRT optical upper limit
  41. GRB 241002A: Swift detection of a burst
  42. GRB 240930B: Fermi GBM Observation
  43. GRB 241001A: Swift ToO observations
  44. GRB 240930B: GRBAlpha detection
  45. GRB 240929A: GRBAlpha detection
  46. EP240930a : KAIT optical upper limit
  47. GRB 241001A : Detection of a soft transient by ECLAIRs onboard SVOM
  48. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  49. EP240930a: EP-FXT follow-up observation update
  50. EP240930a: GOTO optical upper limits
  51. GRB 240929A: SVOM/GRM observation
  52. EP240930a: EP-WXT detection of a fast X-ray transient
  53. IceCube-240929A: Upper limits from a search for additional neutrino events in IceCube
  54. GRB 240929A : Leavitt Observatory optical upper limit
  55. Fermi GRB 240930B: Global MASTER-Net observations report
  56. GRB 240930B: Fermi GBM Final Real-time Localization
  57. IPN triangulation of GRB 240926A
  58. GRB 240825A: LBT optical observations
  59. GRB 240928A: SVOM/GRM observation
  60. Fermi GRB 240930A: Global MASTER-Net observations report
  61. Fermi Gamma-ray Burst Monitor trigger 749362078/240930172 (GRB 240930A) is not a GRB
  62. GRB 240930A: Fermi GBM Final Real-time Localization
  63. Fermi Gamma-ray Burst Monitor trigger 749339671/240929913 is not a GRB
  64. GRB 240929A long GRB detected by INTEGRAL
  65. GRB 240929A: BALROG localization (Fermi Trigger 749332209 / GRB 240929826)
  66. Fermi GRB 240929A: Global MASTER-Net observations report
  67. GRB 240929A: Fermi GBM Final Real-time Localization
  68. Konus-Wind detection of GRB 240912A
  69. Swift Trigger 1256950 is probably not a GRB
  70. Fermi Gamma-ray Burst Monitor trigger 749191601/240928199 is not a GRB
  71. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  72. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  73. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  74. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  75. GRB 240926A: SVOM/GRM observation
  76. Konus-Wind detection of GRB 240905B
  77. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  78. EP240919a / GRB 240919A: SVOM/VT upper limit
  79. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  80. Konus-Wind detection of GRB 240918B
  81. IPN triangulation of GRB 240918B
  82. GRB 240905B: VZLUSAT-2 detection
  83. GRB 240918B: AstroSat CZTI detection
  84. EP240913A/GRB 240913C: AbAO optical upper limit
  85. EP240919a / GRB 240919A: Mondy optical upper limit
  86. EP240913a/GRB 240913C: 1.6m Mephisto observations
  87. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  88. EP240919a / GRB 240919A: REM optical and NIR upper limits
  89. EP240919a / GRB 240919A: KAIT optical upper limit
  90. GRB 240414A: further radio observations with the VLA
  91. GRB 240919A / EP240919a: SVOM/GRM observation
  92. GRB 240910A: radio detection with the VLA
  93. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  94. EP240919a is likely a GRB event (duplicate submission of 37563)
  95. EP240919a is likely a GRB event
  96. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  97. GRB 240918B: Fermi GBM Detection
  98. GRB 240910A: further Swift observations and confirmation of afterglow
  99. Fermi GRB 240918A: Global MASTER-Net observations report
  100. GRB 240918A: Fermi GBM Final Real-time Localization

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