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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"

21980 results found.

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

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