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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"

23693 results found.

  1. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  2. GRB 240930B / EP 240930a: SVOM/GRM observation
  3. Fermi trigger No 749735279: Global MASTER-Net observations report
  4. Fermi trigger No 749630753: Global MASTER-Net observations report
  5. Fermi trigger No 749693019: Global MASTER-Net observations report
  6. GRB 241002B: Swift-XRT observations
  7. GRB 241002A: Swift-BAT refined analysis
  8. Konus-Wind detection of GRB 240926A
  9. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  10. IPN triangulation of GRB 240930B / EP 240930a
  11. GRB 241001A : SVOM/VT optical detection
  12. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  13. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  14. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  15. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  16. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  17. GRB 241002C : MITSuME Akeno optical upper limits
  18. GRB241001A: REM optical/NIR upper limits
  19. GRB 241002A: Swift/UVOT Upper Limits
  20. GRB 241002A: Swift-XRT refined Analysis
  21. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  22. GRB 241002B: GOTO optical counterpart candidate
  23. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  24. GRB 240929A: Liverpool Telescope prompt followup observations
  25. Fermi GRB 241002B: Global MASTER-Net observations report
  26. GRB 241001A: Swift-XRT observations
  27. EP trigger ID 01709064214: the X-ray transient is most likely a stellar flare event
  28. GRB241001A: optical afterglow candidate
  29. GRB 241002A: 1.5m OSN optical upper limit
  30. GRB 241001A: BOOTES-6/DPRT optical upper limit
  31. GRB 241002A: Swift detection of a burst
  32. GRB 240930B: GRBAlpha detection
  33. GRB 240929A: GRBAlpha detection
  34. EP240930a : KAIT optical upper limit
  35. EP240930a: EP-FXT follow-up observation update
  36. EP240930a: GOTO optical upper limits
  37. EP EP240930a: Global MASTER-Net observations report
  38. EP240930a: EP-WXT detection of a fast X-ray transient
  39. LIGO/Virgo/KAGRA S240930df: 1 counterpart neutrino candidate event from an IceCube neutrino search
  40. Fermi GRB 240930B: Global MASTER-Net observations report
  41. GRB 240825A: LBT optical observations
  42. Fermi GRB 240930A: Global MASTER-Net observations report
  43. LIGO/Virgo/KAGRA S240930aa: Identification of a GW compact binary merger candidate
  44. Fermi trigger No 749339671: Global MASTER-Net observations report
  45. GRB 240929A long GRB detected by INTEGRAL
  46. Fermi GRB 240929A: Global MASTER-Net observations report
  47. Integral GRB240929.83: Global MASTER-Net observations report
  48. Konus-Wind detection of GRB 240912A
  49. Swift Trigger 1256950 is probably not a GRB
  50. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  51. Konus-Wind detection of GRB 240905B
  52. GW S240915b and S240919bn : Swift UVOT follow-up
  53. EP240919a / GRB 240919A: SVOM/VT upper limit
  54. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  55. EP240918b and EP240918c: EP-FXT follow-up observations
  56. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  57. Konus-Wind detection of GRB 240918B
  58. IPN triangulation of GRB 240918B
  59. GRB 240905B: VZLUSAT-2 detection
  60. EP trigger ID 01709059262: correction to the observation start time and source localization
  61. EP trigger ID 01709059262: the X-ray transient is likely a stellar flare event
  62. LIGO/Virgo/KAGRA S240924a: Identification of a GW compact binary merger candidate
  63. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  64. LIGO/Virgo S240919bn: GOTO optical upper limits
  65. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  66. GRB 240918B: AstroSat CZTI detection
  67. LIGO/Virgo/KAGRA S240922df: Identification of a GW compact binary merger candidate
  68. EP240919a: EP-FXT follow-up observation update
  69. EP240913a/GRB 240913C: 1.6m Mephisto observations
  70. EP240918a: SVOM/VT upper limit
  71. EP240919a / GRB 240919A: REM optical and NIR upper limits
  72. EP240919a / GRB 240919A: KAIT optical upper limit
  73. EP240918b and EP240918c: Optical upper limits with Kinder observations
  74. GRB 240414A: further radio observations with the VLA
  75. EP240919a: Optical upper limit with Kinder observations
  76. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  77. EP EP240919a: Global MASTER-Net observations report
  78. GRB 240910A: radio detection with the VLA
  79. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  80. EP240919a: GOTO optical upper limits
  81. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  82. EP240919a: EP-WXT detection of a fast X-ray transient
  83. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  84. EP240918a: EP observation update
  85. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  86. EP240918a: Swift-XRT observation
  87. Fermi GRB 240918A: Global MASTER-Net observations report
  88. EP EP240918a: Global MASTER-Net observations report
  89. EP240918a: Optical upper limits with Kinder observations
  90. EP240918a: GMG Optical Upper Limit
  91. GRB 240916A: GRBAlpha detection
  92. GRB 240914B: GRBAlpha detection
  93. EP240918a: an X-ray transient detected by Einstein Probe
  94. GRB 240916A: NOT optical observation
  95. GRB 240912A: Swift-BAT refined analysis
  96. IPN triangulation of GRB 240913C / EP 240913a
  97. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  98. LIGO/Virgo/KAGRA S240917cb: Identification of a GW compact binary merger candidate
  99. GRB 240821A: radio observation with the VLA
  100. GRB 240916A: Swift-XRT afterglow detection

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