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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"

37333 results found.

  1. GRB 241001A : SVOM/VT optical detection
  2. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  3. GRB 241002D: SVOM/GRM observation
  4. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  5. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  6. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  7. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  8. GRB 241002C : MITSuME Akeno optical upper limits
  9. GRB241001A: REM optical/NIR upper limits
  10. GRB 241002A: Swift/UVOT Upper Limits
  11. GRB 241002A: Swift-XRT refined Analysis
  12. GRB 241002A: LCOGT Optical Upper Limits
  13. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  14. GRB 241001A: Swift/UVOT Detection
  15. GRB 241001A: VLT/X-shooter redshift
  16. GRB 241002B: GOTO optical counterpart candidate
  17. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  18. GRB 241001A: correction to GCN 37667
  19. GRB 240929A: Liverpool Telescope prompt followup observations
  20. Fermi GRB 241002B: Global MASTER-Net observations report
  21. GRB 241001A: Swift-XRT observations
  22. GRB 241002B: Fermi GBM Final Real-time Localization
  23. GRB241001A: optical afterglow candidate
  24. GRB 241002A: 1.5m OSN optical upper limit
  25. GRB 241002A: Enhanced Swift-XRT position
  26. GRB 241001A: BOOTES-6/DPRT optical upper limit
  27. GRB 241002A: Swift detection of a burst
  28. GRB 240930B: Fermi GBM Observation
  29. GRB 241001A: Swift ToO observations
  30. GRB 240930B: GRBAlpha detection
  31. GRB 240929A: GRBAlpha detection
  32. EP240930a : KAIT optical upper limit
  33. GRB 241001A : Detection of a soft transient by ECLAIRs onboard SVOM
  34. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  35. EP240930a: EP-FXT follow-up observation update
  36. EP240930a: GOTO optical upper limits
  37. GRB 240929A: SVOM/GRM observation
  38. EP240930a: EP-WXT detection of a fast X-ray transient
  39. GRB 240929A : Leavitt Observatory optical upper limit
  40. Fermi GRB 240930B: Global MASTER-Net observations report
  41. GRB 240930B: Fermi GBM Final Real-time Localization
  42. IPN triangulation of GRB 240926A
  43. GRB 240825A: LBT optical observations
  44. GRB 240928A: SVOM/GRM observation
  45. Fermi GRB 240930A: Global MASTER-Net observations report
  46. Fermi Gamma-ray Burst Monitor trigger 749362078/240930172 (GRB 240930A) is not a GRB
  47. GRB 240930A: Fermi GBM Final Real-time Localization
  48. Fermi Gamma-ray Burst Monitor trigger 749339671/240929913 is not a GRB
  49. GRB 240929A long GRB detected by INTEGRAL
  50. GRB 240929A: BALROG localization (Fermi Trigger 749332209 / GRB 240929826)
  51. Fermi GRB 240929A: Global MASTER-Net observations report
  52. GRB 240929A: Fermi GBM Final Real-time Localization
  53. Konus-Wind detection of GRB 240912A
  54. Swift Trigger 1256950 is probably not a GRB
  55. Fermi Gamma-ray Burst Monitor trigger 749191601/240928199 is not a GRB
  56. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  57. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  58. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  59. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  60. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  61. GRB 240926A: SVOM/GRM observation
  62. Konus-Wind detection of GRB 240905B
  63. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  64. EP240919a / GRB 240919A: SVOM/VT upper limit
  65. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  66. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  67. Konus-Wind detection of GRB 240918B
  68. IPN triangulation of GRB 240918B
  69. GRB 240905B: VZLUSAT-2 detection
  70. GRB 240918B: AstroSat CZTI detection
  71. EP240913A/GRB 240913C: AbAO optical upper limit
  72. EP240919a / GRB 240919A: Mondy optical upper limit
  73. EP240913a/GRB 240913C: 1.6m Mephisto observations
  74. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  75. EP240919a / GRB 240919A: REM optical and NIR upper limits
  76. EP240919a / GRB 240919A: KAIT optical upper limit
  77. EP240918b and EP240918c: Optical upper limits with Kinder observations
  78. GRB 240414A: further radio observations with the VLA
  79. EP240919a: Optical upper limit with Kinder observations
  80. GRB 240919A / EP240919a: SVOM/GRM observation
  81. GRB 240910A: radio detection with the VLA
  82. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  83. EP240919a is likely a GRB event (duplicate submission of 37563)
  84. EP240919a is likely a GRB event
  85. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  86. GRB 240918B: Fermi GBM Detection
  87. GRB 240910A: further Swift observations and confirmation of afterglow
  88. Fermi GRB 240918A: Global MASTER-Net observations report
  89. GRB 240918A: Fermi GBM Final Real-time Localization
  90. EP240918a: Optical upper limits with Kinder observations
  91. GRB 240916A: GRBAlpha detection
  92. GRB 240914B: GRBAlpha detection
  93. GRB 240916A: NOT optical observation
  94. GRB 240912A: Swift-BAT refined analysis
  95. IPN triangulation of GRB 240913C / EP 240913a
  96. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  97. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  98. GRB 240916A: Fermi GBM Observation
  99. LIGO/Virgo/KAGRA S240917cb: Identification of a GW compact binary merger candidate
  100. GRB 240821A: radio observation with the VLA

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