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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"

23687 results found.

  1. GRB 241002A: Swift-BAT refined analysis
  2. Konus-Wind detection of GRB 240926A
  3. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  4. IPN triangulation of GRB 240930B / EP 240930a
  5. GRB 241001A : SVOM/VT optical detection
  6. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  7. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  8. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  9. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  10. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  11. GRB 241002C : MITSuME Akeno optical upper limits
  12. GRB241001A: REM optical/NIR upper limits
  13. GRB 241002A: Swift/UVOT Upper Limits
  14. GRB 241002A: Swift-XRT refined Analysis
  15. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  16. GRB 241002B: GOTO optical counterpart candidate
  17. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  18. GRB 240929A: Liverpool Telescope prompt followup observations
  19. Fermi GRB 241002B: Global MASTER-Net observations report
  20. GRB 241001A: Swift-XRT observations
  21. EP trigger ID 01709064214: the X-ray transient is most likely a stellar flare event
  22. GRB241001A: optical afterglow candidate
  23. GRB 241002A: 1.5m OSN optical upper limit
  24. GRB 241001A: BOOTES-6/DPRT optical upper limit
  25. GRB 241002A: Swift detection of a burst
  26. GRB 240930B: GRBAlpha detection
  27. GRB 240929A: GRBAlpha detection
  28. EP240930a : KAIT optical upper limit
  29. EP240930a: EP-FXT follow-up observation update
  30. EP240930a: GOTO optical upper limits
  31. EP EP240930a: Global MASTER-Net observations report
  32. EP240930a: EP-WXT detection of a fast X-ray transient
  33. LIGO/Virgo/KAGRA S240930df: 1 counterpart neutrino candidate event from an IceCube neutrino search
  34. Fermi GRB 240930B: Global MASTER-Net observations report
  35. GRB 240825A: LBT optical observations
  36. Fermi GRB 240930A: Global MASTER-Net observations report
  37. LIGO/Virgo/KAGRA S240930aa: Identification of a GW compact binary merger candidate
  38. Fermi trigger No 749339671: Global MASTER-Net observations report
  39. GRB 240929A long GRB detected by INTEGRAL
  40. Fermi GRB 240929A: Global MASTER-Net observations report
  41. Integral GRB240929.83: Global MASTER-Net observations report
  42. Konus-Wind detection of GRB 240912A
  43. Swift Trigger 1256950 is probably not a GRB
  44. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  45. Konus-Wind detection of GRB 240905B
  46. GW S240915b and S240919bn : Swift UVOT follow-up
  47. EP240919a / GRB 240919A: SVOM/VT upper limit
  48. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  49. EP240918b and EP240918c: EP-FXT follow-up observations
  50. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  51. Konus-Wind detection of GRB 240918B
  52. IPN triangulation of GRB 240918B
  53. GRB 240905B: VZLUSAT-2 detection
  54. EP trigger ID 01709059262: correction to the observation start time and source localization
  55. EP trigger ID 01709059262: the X-ray transient is likely a stellar flare event
  56. LIGO/Virgo/KAGRA S240924a: Identification of a GW compact binary merger candidate
  57. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  58. LIGO/Virgo S240919bn: GOTO optical upper limits
  59. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  60. GRB 240918B: AstroSat CZTI detection
  61. LIGO/Virgo/KAGRA S240922df: Identification of a GW compact binary merger candidate
  62. EP240919a: EP-FXT follow-up observation update
  63. EP240913a/GRB 240913C: 1.6m Mephisto observations
  64. EP240918a: SVOM/VT upper limit
  65. EP240919a / GRB 240919A: REM optical and NIR upper limits
  66. EP240919a / GRB 240919A: KAIT optical upper limit
  67. EP240918b and EP240918c: Optical upper limits with Kinder observations
  68. GRB 240414A: further radio observations with the VLA
  69. EP240919a: Optical upper limit with Kinder observations
  70. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  71. EP EP240919a: Global MASTER-Net observations report
  72. GRB 240910A: radio detection with the VLA
  73. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  74. EP240919a: GOTO optical upper limits
  75. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  76. EP240919a: EP-WXT detection of a fast X-ray transient
  77. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  78. EP240918a: EP observation update
  79. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  80. EP240918a: Swift-XRT observation
  81. Fermi GRB 240918A: Global MASTER-Net observations report
  82. EP EP240918a: Global MASTER-Net observations report
  83. EP240918a: Optical upper limits with Kinder observations
  84. EP240918a: GMG Optical Upper Limit
  85. GRB 240916A: GRBAlpha detection
  86. GRB 240914B: GRBAlpha detection
  87. EP240918a: an X-ray transient detected by Einstein Probe
  88. GRB 240916A: NOT optical observation
  89. GRB 240912A: Swift-BAT refined analysis
  90. IPN triangulation of GRB 240913C / EP 240913a
  91. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  92. LIGO/Virgo/KAGRA S240917cb: Identification of a GW compact binary merger candidate
  93. GRB 240821A: radio observation with the VLA
  94. GRB 240916A: Swift-XRT afterglow detection
  95. LIGO/Virgo/KAGRA S240916ar: Identification of a GW compact binary merger candidate
  96. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  97. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  98. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  99. EP EP240913a: Global MASTER-Net observations report
  100. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations

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