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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 241025A: SAO RAS optical observations
  2. GRB 241026A: Las Cumbres optical detection
  3. EP241021a: further SAO RAS optical observations
  4. GRB 241026A: Swift-XRT refined Analysis
  5. EP EP241026b: Global MASTER-Net observations report
  6. GRB 241026A: KAIT optical observations
  7. Fermi trigger No 751616906: Global MASTER-Net observations report
  8. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  9. GRB 241026A: SAO RAS observations of possible optical afterglow
  10. Fermi GRB 241026A: Global MASTER-Net observations report
  11. GRB 241026A: Swift detection of a burst
  12. Swift GRB241026.95: Global MASTER-Net observations report
  13. EP241021a: optical follow-up observations with Xinglong Observatory
  14. GRB 241025A: COLIBRÍ Detection of the Afterglow
  15. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  16. Fermi trigger No 751563375: Global MASTER-Net observations report
  17. Fermi trigger No 751554401: Global MASTER-Net observations report
  18. EP 241021a: Swift-XRT observations
  19. Fermi GRB 241025A: Global MASTER-Net observations report
  20. Swift GRB 241025A: Global MASTER-Net observations report
  21. EP241025a (GRB 241025A): EP observations update
  22. GRB 241025A : SVOM/VT optical afterglow observations
  23. GRB 241025A: NOT spectroscopic redshift of z = 4.20
  24. GRB 241025A: DDOTI Afterglow detection
  25. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  26. GRB 241025A: TRT optical afterglow observation
  27. Fermi GRB 241024B: Global MASTER-Net observations report
  28. GRB 241025A: Swift detection of a burst with an optical counterpart
  29. EP241021a: No Detection in Fermi-GBM Observation
  30. Fermi trigger No 751449953: Global MASTER-Net observations report
  31. EP241021a: SAO RAS optical observations
  32. EP241021a: KAIT optical observations
  33. EP241021a: GSP detects optical candidate counterpart
  34. EP241021a: Optical upper limits with Kinder observations
  35. EP241021a: TRT optical observations
  36. EP241021a: NOT likely optical counterpart
  37. EP EP241021a: Global MASTER-Net observations report
  38. GRB 241018A: EP-FXT afterglow detection
  39. EP241021a: GOTO optical upper limits
  40. EP241021a: EP detection of a fast X-ray transient
  41. Konus-Wind detection of GRB 241018A
  42. GRB 241018A/sb24101802: Mephisto optical upper limit
  43. GRB 241018A: BOOTES-4/MET optical upper limit
  44. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  45. GRB 241018A: Swift-XRT observations
  46. GRB 241018A: REM optical/NIR upper limits
  47. GRB 241017A: SVOM/VT follow-up and optical upper limit
  48. GRB 241018A: SVOM/VT follow-up and optical candidate
  49. GRB 241018A: X-ray afterglow candidate observed by MXT
  50. GRB 241017A: Swift-XRT observations
  51. GRB 241001A: EP-FXT afterglow detection
  52. GRB241017A: TOO Observations by SVOM/MXT
  53. GRB 241017A: J-band upper limit from WINTER
  54. Fermi trigger No 750788395: Global MASTER-Net observations report
  55. Fermi GRB 241016B: Global MASTER-Net observations report
  56. Fermi GRB 241016A: Global MASTER-Net observations report
  57. IceCube Alert 241016.04: Global MASTER-Net observations report
  58. GRB 241010A: Swift-BAT refined analysis
  59. GRB 240916A: radio detection with the VLA
  60. GRB241013A: REM observations
  61. GRB 241013B: SVOM/GRM observation
  62. Fermi GRB 241013B: Global MASTER-Net observations report
  63. Integral GRB241013.04: Global MASTER-Net observations report
  64. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  65. GRB 241009A: GRANDMA optical upper limits
  66. GRB 241009A: Swift-XRT afterglow detection
  67. GRB 241010A: Swift-XRT refined Analysis
  68. Fermi trigger No 750211959: Global MASTER-Net observations report
  69. Swift GRB 241010A: Global MASTER-Net observations report
  70. Fermi trigger No 750291012: Global MASTER-Net observations report
  71. GRB 241010A: J-band observations with WINTER
  72. Fermi GRB 241010B: Global MASTER-Net observations report
  73. GRB 241010A: LCO optical observations
  74. GRB 241010A: Swift detection of a burst with an optical counterpart
  75. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  76. GRB 241006A: Swift-BAT refined analysis
  77. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  78. GRB 241008A: Fermi-LAT detection
  79. GRB 241002B: Swift-XRT afterglow detection
  80. LIGO/Virgo/KAGRA S241009an: Identification of a GW compact binary merger candidate
  81. Fermi GRB 241008A: Global MASTER-Net observations report
  82. GRB 241006A: GRANDMA optical upper limits
  83. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  84. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  85. GRB 241006A: Swift-XRT refined Analysis
  86. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  87. GRB 241006A: SVOM/VT follow-up and optical upper limit
  88. LIGO/Virgo/KAGRA S241007bw: Identification of a GW compact binary merger candidate
  89. IceCube Alert 241006.94: Global MASTER-Net observations report
  90. GRB 241001A: Swift-XRT afterglow detection
  91. GRB 241006A: Swift detection of a burst
  92. Swift GRB241006.91: Global MASTER-Net observations report
  93. LIGO/Virgo/KAGRA S241006k: Identification of a GW compact binary merger candidate
  94. Fermi trigger No 749721670: Global MASTER-Net observations report
  95. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  96. GRB 240930B / EP 240930a: SVOM/GRM observation
  97. Fermi trigger No 749735279: Global MASTER-Net observations report
  98. Fermi trigger No 749630753: Global MASTER-Net observations report
  99. Fermi trigger No 749693019: Global MASTER-Net observations report
  100. GRB 241002B: Swift-XRT observations

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