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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"

21978 results found.

  1. EP 241021a: Swift-XRT observations
  2. EP241021a: optical follow-up observations with the Liverpool Telescope
  3. Fermi GRB 241025A: Global MASTER-Net observations report
  4. Swift GRB 241025A: Global MASTER-Net observations report
  5. EP241025a (GRB 241025A): EP observations update
  6. GRB 241025A : SVOM/VT optical afterglow observations
  7. EP 241021A: Swift ToO observations
  8. EP241021a: Liverpool Telescope optical follow-up observations
  9. GRB 241001A: JWST spectroscopic identification of a supernova counterpart
  10. GRB 241025A: TRT optical afterglow observation
  11. Fermi GRB 241024B: Global MASTER-Net observations report
  12. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  13. GRB 241001A: ATCA radio observations
  14. EP241021a: No Detection in Fermi-GBM Observation
  15. Fermi trigger No 751449953: Global MASTER-Net observations report
  16. EP241021a: SAO RAS optical observations
  17. EP241021a: KAIT optical observations
  18. EP241021a: Optical counterpart observations with the Liverpool Telescope
  19. EP241021a: 1.3m DFOT Optical observations
  20. EP241021a: GSP detects optical candidate counterpart
  21. EP241021a: Optical upper limits with Kinder observations
  22. EP241021a: TRT optical observations
  23. GRB 241018A: SVOM/C-GFT optical observations
  24. EP241021a: NOT likely optical counterpart
  25. EP EP241021a: Global MASTER-Net observations report
  26. GRB241017A: 1.3m DFOT optical upper limit
  27. GRB 241018A: 1.3m DFOT Optical upper limit
  28. EP241021a: GOTO optical upper limits
  29. EP241021a: EP detection of a fast X-ray transient
  30. GRB 241017A/sb24101702: Mephisto optical upper limit
  31. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  32. GRB 241018A: GROWTH-India telescope optical upper limit
  33. GRB 241018A: Swift-XRT observations
  34. GRB 241018A: REM optical/NIR upper limits
  35. GRB 241018A: NOT optical observations
  36. GRB 241017A: SVOM/VT follow-up and optical upper limit
  37. GRB 241018A: SVOM/VT follow-up and optical candidate
  38. GRB 241018A: Swift ToO observations
  39. GRB 241018A: X-ray afterglow candidate observed by MXT
  40. GRB 241016B: Fermi GBM Observations
  41. GRB 241017A: Swift-XRT observations
  42. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  43. GRB241017A: TOO Observations by SVOM/MXT
  44. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  45. GRB 241017A: J-band upper limit from WINTER
  46. Fermi trigger No 750788395: Global MASTER-Net observations report
  47. GRB 241017A: Swift ToO observations
  48. Fermi GRB 241016B: Global MASTER-Net observations report
  49. Fermi GRB 241016A: Global MASTER-Net observations report
  50. IceCube Alert 241016.04: Global MASTER-Net observations report
  51. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  52. GRB 240916A: radio detection with the VLA
  53. GRB241013A: REM observations
  54. Fermi GRB 241013B: Global MASTER-Net observations report
  55. Integral GRB241013.04: Global MASTER-Net observations report
  56. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  57. GRB 241009A: GRANDMA optical upper limits
  58. GRB 241009A: Swift-XRT afterglow detection
  59. GRB 241010A: JinShan optical observations and potential host galaxy
  60. GRB 241006A: ATCA Radio Upper Limits
  61. Fermi trigger No 750211959: Global MASTER-Net observations report
  62. Swift GRB 241010A: Global MASTER-Net observations report
  63. Fermi trigger No 750291012: Global MASTER-Net observations report
  64. GRB 241010A: J-band observations with WINTER
  65. Fermi GRB 241010B: Global MASTER-Net observations report
  66. GRB 241010A: LCO optical observations
  67. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  68. GRB 241009A: Swift ToO observations
  69. GRB 241002B: Swift-XRT afterglow detection
  70. GRB 241002A: NOT optical upper limits
  71. Fermi GRB 241008A: Global MASTER-Net observations report
  72. IceCube-241006A: No candidates from the Zwicky Transient Facility
  73. GRB 241006A: GRANDMA optical upper limits
  74. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  75. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  76. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  77. GRB 240910A: LBT optical observations
  78. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  79. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  80. GRB 241006A: PRIME near-infrared upper limits
  81. GRB 241006A: Swift/UVOT Upper Limits
  82. GRB 241006A: SVOM/VT follow-up and optical upper limit
  83. IceCube Alert 241006.94: Global MASTER-Net observations report
  84. GRB 241001A: Swift-XRT afterglow detection
  85. Swift GRB241006.91: Global MASTER-Net observations report
  86. Fermi trigger No 749721670: Global MASTER-Net observations report
  87. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  88. GRB 241002B: Fermi GBM Observation
  89. Fermi trigger No 749735279: Global MASTER-Net observations report
  90. Fermi trigger No 749630753: Global MASTER-Net observations report
  91. Fermi trigger No 749693019: Global MASTER-Net observations report
  92. GRB 241002B: Swift-XRT observations
  93. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  94. GRB 241002B: Swift ToO observations
  95. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  96. GRB 241002B: PRIME near-infrared detection
  97. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  98. GRB 241002C: Swift ToO observations
  99. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  100. GRB 241001A : SVOM/VT optical detection

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