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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"

12398 results found.

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

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