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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"

12399 results found.

  1. IceCube Alert 241006.94: Global MASTER-Net observations report
  2. Swift GRB241006.91: Global MASTER-Net observations report
  3. GRB 240930B: SVOM/C-GFT optical upper limit
  4. Fermi trigger No 749721670: Global MASTER-Net observations report
  5. Fermi trigger No 749735279: Global MASTER-Net observations report
  6. Fermi trigger No 749630753: Global MASTER-Net observations report
  7. Fermi trigger No 749693019: Global MASTER-Net observations report
  8. GRB 241002B: Swift-XRT observations
  9. GRB 241002C: SVOM/C-GFT optical upper limit
  10. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  11. Konus-Wind detection of GRB 240926A
  12. GRB 241002C : MITSuME Akeno optical upper limits
  13. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  14. GRB241001A: REM optical/NIR upper limits
  15. GRB 241002A: Swift/UVOT Upper Limits
  16. GRB 241002A: LCOGT Optical Upper Limits
  17. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  18. Fermi GRB 241002B: Global MASTER-Net observations report
  19. GRB 241001A: Swift-XRT observations
  20. GRB 241002A: 1.5m OSN optical upper limit
  21. GRB 241001A: BOOTES-6/DPRT optical upper limit
  22. EP240930a : KAIT optical upper limit
  23. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  24. EP240930a: GOTO optical upper limits
  25. EP EP240930a: Global MASTER-Net observations report
  26. IceCube-240929A: Upper limits from a search for additional neutrino events in IceCube
  27. GRB 240929A : Leavitt Observatory optical upper limit
  28. Fermi GRB 240930B: Global MASTER-Net observations report
  29. Fermi GRB 240930A: Global MASTER-Net observations report
  30. Fermi trigger No 749339671: Global MASTER-Net observations report
  31. Fermi GRB 240929A: Global MASTER-Net observations report
  32. Integral GRB240929.83: Global MASTER-Net observations report
  33. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  35. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  36. Konus-Wind detection of GRB 240905B
  37. GW S240915b and S240919bn : Swift UVOT follow-up
  38. EP240919a / GRB 240919A: SVOM/VT upper limit
  39. Konus-Wind detection of GRB 240918B
  40. LIGO/Virgo S240919bn: GOTO optical upper limits
  41. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  42. EP240913A/GRB 240913C: AbAO optical upper limit
  43. EP240919a / GRB 240919A: Mondy optical upper limit
  44. EP240913a/GRB 240913C: 1.6m Mephisto observations
  45. EP240918a: SVOM/VT upper limit
  46. EP240919a / GRB 240919A: REM optical and NIR upper limits
  47. EP240919a / GRB 240919A: KAIT optical upper limit
  48. EP240918b and EP240918c: Optical upper limits with Kinder observations
  49. EP240919a: Optical upper limit with Kinder observations
  50. EP EP240919a: Global MASTER-Net observations report
  51. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  52. EP240919a: GOTO optical upper limits
  53. EP240919a: JinShan optical upper limits
  54. GRB 240910A: further Swift observations and confirmation of afterglow
  55. EP240918a: Swift-XRT observation
  56. Fermi GRB 240918A: Global MASTER-Net observations report
  57. EP EP240918a: Global MASTER-Net observations report
  58. EP240918a: JinShan optical upper limits
  59. EP240918a: YAHPT Optical Upper Limit
  60. EP240918a: Optical upper limits with Kinder observations
  61. EP240918a: GMG Optical Upper Limit
  62. GRB 240821A: radio observation with the VLA
  63. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  64. EP EP240913a: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  66. EP240913a: VLT/HAWK-I near-infrared upper limits
  67. EP240913a/GRB 240913C: KAIT optical upper limit
  68. GRB 240914A: Swift-XRT observations
  69. EP240913a: NOT optical upper limits
  70. EP240913a: JinShan optical upper limits
  71. GRB 240905E: further NOT optical observations
  72. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  73. GRB 240912A: Swift/UVOT Detection
  74. Fermi trigger No 747920561: Global MASTER-Net observations report
  75. GRB 240911A: Swift-XRT observations
  76. Fermi GRB 240913A: Global MASTER-Net observations report
  77. GRB 240912A: J-band observations with WINTER
  78. Swift GRB 240912A: Global MASTER-Net observations report
  79. Fast X-ray Transient EP240801a: GMRT radio observations
  80. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  81. GRB 240825A: 7DT Optical Upper Limit
  82. GRB 240905E: SVOM/VT optical observations
  83. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  84. EP240908a: Mondy and AbAO follow-up observations
  85. Fermi GRB 240910A: Global MASTER-Net observations report
  86. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  87. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  88. EP EP240908a: Global MASTER-Net observations report
  89. Fermi trigger No 747553301: Global MASTER-Net observations report
  90. EP240908a: TRT optical upper limit
  91. GRB 240905B: GOTO optical upper limits
  92. Fermi GRB 240908A: Global MASTER-Net observations report
  93. GRB 240905E: GIT optical upper limit
  94. GRB 240905B: Swift-XRT observations
  95. GRB 240905E: Gaoyazi/GOT optical upper limits
  96. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  97. GRB 240905E: J-band observations with WINTER
  98. GRB 240905E: AKO Optical Upper Limit
  99. GRB 240905E: SVOM/C-GFT optical upper limit
  100. GRB 240905E: OHP/MISTRAL T193 optical upper limit

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