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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"

12403 results found.

  1. Fermi GRB 240605C: Global MASTER-Net observations report
  2. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  3. Fermi GRB 240603C: Global MASTER-Net observations report
  4. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  5. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  6. Swift Trigger 1232465: consistent with noise
  7. Fermi GRB 240602A: Global MASTER-Net observations report
  8. Swift Trigger 1232465 is not a GRB
  9. LXT 240528A: GSP optical upper limit
  10. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  11. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  12. GRB 240529A: Swift/UVOT Detection
  13. GRB 240527B: Swift-XRT afterglow detection
  14. Swift GRB240529.12: Global MASTER-Net observations report
  15. Fermi GRB 240527A: Global MASTER-Net observations report
  16. LAT GRB240527.59: Global MASTER-Net observations report
  17. Fermi GRB 240527B: Global MASTER-Net observations report
  18. Fermi trigger No 738348224: Global MASTER-Net observations report
  19. Fermi trigger No 738330463: Global MASTER-Net observations report
  20. GRB 240523A: Swift detection of a burst
  21. Fermi trigger No 737996942: Global MASTER-Net observations report
  22. EP240518a: GSP optical upper limit
  23. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  24. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  25. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  26. IceCube-Cascade 240518A: Upper limits from a search for additional neutrino events in IceCube
  27. GRB 240516A: Swift/UVOT Upper Limits
  28. Fermi trigger No 737788024: Global MASTER-Net observations report
  29. Fermi GRB 240517A: Global MASTER-Net observations report
  30. GRB 240516A ATCA radio observations
  31. GRB 240516A: Swift-XRT refined Analysis
  32. Fermi trigger No 737559855: Global MASTER-Net observations report
  33. GRB 240516A: GOTO optical upper limit
  34. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  35. Fermi trigger No 737523389: Global MASTER-Net observations report
  36. GRB 240516A: Swift detection of a burst
  37. Swift GRB240516.15: Global MASTER-Net observations report
  38. Fermi trigger No 737476171: Global MASTER-Net observations report
  39. MAXI GRB240514.78: Global MASTER-Net observations report
  40. GRB 240514E: MAXI/GSC detection of a probable afterglow
  41. LIGO/Virgo/KAGRA S240422ed: Las Cumbres Observatory Follow-up Observations of the Localization Region
  42. GRB 240513A: Swift-XRT observations
  43. Fermi GRB 240514B: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  45. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  46. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  47. LAT GRB240513.31: Global MASTER-Net observations report
  48. Fermi GRB 240513B: Global MASTER-Net observations report
  49. Fermi trigger No 737277727: Global MASTER-Net observations report
  50. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  51. Fermi trigger No 737258655: Global MASTER-Net observations report
  52. GRB 240511A: J-band observations with WINTER
  53. Fermi trigger No 737247400: Global MASTER-Net observations report
  54. Fermi trigger No 737244199: Global MASTER-Net observations report
  55. Fermi trigger No 737218721: Global MASTER-Net observations report
  56. Fermi trigger No 737196587: Global MASTER-Net observations report
  57. Fermi trigger No 737168073: Global MASTER-Net observations report
  58. GRB 240511A : MITSuME Akeno optical upper limits
  59. Fermi trigger No 737173236: Global MASTER-Net observations report
  60. Fermi GRB 240511A: Global MASTER-Net observations report
  61. Swift GRB 240511A: Global MASTER-Net observations report
  62. Fermi trigger No 737105243: Global MASTER-Net observations report
  63. Fermi trigger No 737152719: Global MASTER-Net observations report
  64. GRB 240511A: Swift detection of a burst
  65. Fermi trigger No 737102480: Global MASTER-Net observations report
  66. Fermi trigger No 737111207: Global MASTER-Net observations report
  67. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  68. LIGO/Virgo/KAGRA S240422ed: P200 observations of AT2024hit
  69. LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
  70. Fermi trigger No 736967879: Global MASTER-Net observations report
  71. EP240506a: Xinglong optical upper limit
  72. EP240506a: CrAO ZTSH optical upper limit
  73. EP240506a: TRT optical upper limit
  74. EP240506a: BOOTES Network optical upper limit
  75. LIGO/Virgo/KAGRA S240422ed: Upper limits from a two-week IceCube neutrino search
  76. Fermi trigger No 736733320: Global MASTER-Net observations report
  77. EP240506a: Optical upper limit with Kinder observations
  78. GRB 240502A: 1.3m DFOT Optical upper limit
  79. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  80. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfr and AT2024hfs
  81. Fermi trigger No 736564880: Global MASTER-Net observations report
  82. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  83. Fermi trigger No 736461232: Global MASTER-Net observations report
  84. Fermi GRB 240504A: Global MASTER-Net observations report
  85. Fermi trigger No 736472503: Global MASTER-Net observations report
  86. Fermi trigger No 736387941: Global MASTER-Net observations report
  87. GRB 240502A: GOTO optical upper limit
  88. Fermi trigger No 736379109: Global MASTER-Net observations report
  89. GRB 240415A 1.3m DFOT Optical upper limit
  90. Fermi GRB 240502B: Global MASTER-Net observations report
  91. Fermi GRB 240502A: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  93. Integral GRB240502.23: Global MASTER-Net observations report
  94. LIGO/Virgo/KAGRA S240422ed: Host redshifts of AT2024hfq, AT2024hfu, and AT2024hmo from DBSP
  95. Fermi GRB 240501A: Global MASTER-Net observations report
  96. Fermi trigger No 736197684: Global MASTER-Net observations report
  97. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  98. Additional DECam GW-MMADS Candidates from three nights of observations
  99. Fermi-LAT gamma-ray observations of IceCube-240424A
  100. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a

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