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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"

20996 results found.

  1. Fermi GRB 241025A: Global MASTER-Net observations report
  2. Swift GRB 241025A: Global MASTER-Net observations report
  3. EP241025a (GRB 241025A): EP observations update
  4. GRB 241025A : SVOM/VT optical afterglow observations
  5. EP 241021A: Swift ToO observations
  6. EP241021a: Liverpool Telescope optical follow-up observations
  7. GRB 241001A: JWST spectroscopic identification of a supernova counterpart
  8. GRB 241025A: TRT optical afterglow observation
  9. Fermi GRB 241024B: Global MASTER-Net observations report
  10. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  11. GRB 241001A: ATCA radio observations
  12. Fermi trigger No 751449953: Global MASTER-Net observations report
  13. EP241021a: SAO RAS optical observations
  14. EP241021a: KAIT optical observations
  15. EP241021a: Optical counterpart observations with the Liverpool Telescope
  16. EP241021a: 1.3m DFOT Optical observations
  17. EP241021a: GSP detects optical candidate counterpart
  18. EP241021a: Optical upper limits with Kinder observations
  19. EP241021a: TRT optical observations
  20. GRB 241018A: SVOM/C-GFT optical observations
  21. EP241021a: NOT likely optical counterpart
  22. EP EP241021a: Global MASTER-Net observations report
  23. GRB241017A: 1.3m DFOT optical upper limit
  24. GRB 241018A: 1.3m DFOT Optical upper limit
  25. EP241021a: GOTO optical upper limits
  26. EP241021a: EP detection of a fast X-ray transient
  27. GRB 241017A/sb24101702: Mephisto optical upper limit
  28. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  29. GRB 241018A: GROWTH-India telescope optical upper limit
  30. GRB 241018A: Swift-XRT observations
  31. GRB 241018A: REM optical/NIR upper limits
  32. GRB 241018A: NOT optical observations
  33. GRB 241017A: SVOM/VT follow-up and optical upper limit
  34. GRB 241018A: SVOM/VT follow-up and optical candidate
  35. GRB 241018A: Swift ToO observations
  36. GRB 241018A: X-ray afterglow candidate observed by MXT
  37. GRB 241016B: Fermi GBM Observations
  38. GRB 241017A: Swift-XRT observations
  39. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  40. GRB241017A: TOO Observations by SVOM/MXT
  41. GRB 241017A: J-band upper limit from WINTER
  42. Fermi trigger No 750788395: Global MASTER-Net observations report
  43. GRB 241017A: Swift ToO observations
  44. Fermi GRB 241016B: Global MASTER-Net observations report
  45. Fermi GRB 241016A: Global MASTER-Net observations report
  46. IceCube Alert 241016.04: Global MASTER-Net observations report
  47. GRB 240916A: radio detection with the VLA
  48. GRB241013A: REM observations
  49. Fermi GRB 241013B: Global MASTER-Net observations report
  50. Integral GRB241013.04: Global MASTER-Net observations report
  51. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  52. GRB 241009A: GRANDMA optical upper limits
  53. GRB 241009A: Swift-XRT afterglow detection
  54. GRB 241010A: JinShan optical observations and potential host galaxy
  55. GRB 241006A: ATCA Radio Upper Limits
  56. Fermi trigger No 750211959: Global MASTER-Net observations report
  57. Swift GRB 241010A: Global MASTER-Net observations report
  58. Fermi trigger No 750291012: Global MASTER-Net observations report
  59. GRB 241010A: J-band observations with WINTER
  60. Fermi GRB 241010B: Global MASTER-Net observations report
  61. GRB 241010A: LCO optical observations
  62. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  63. GRB 241009A: Swift ToO observations
  64. GRB 241002B: Swift-XRT afterglow detection
  65. GRB 241002A: NOT optical upper limits
  66. Fermi GRB 241008A: Global MASTER-Net observations report
  67. IceCube-241006A: No candidates from the Zwicky Transient Facility
  68. GRB 241006A: GRANDMA optical upper limits
  69. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  70. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  71. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  72. GRB 240910A: LBT optical observations
  73. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  74. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  75. GRB 241006A: PRIME near-infrared upper limits
  76. GRB 241006A: Swift/UVOT Upper Limits
  77. GRB 241006A: SVOM/VT follow-up and optical upper limit
  78. IceCube Alert 241006.94: Global MASTER-Net observations report
  79. GRB 241001A: Swift-XRT afterglow detection
  80. Swift GRB241006.91: Global MASTER-Net observations report
  81. Fermi trigger No 749721670: Global MASTER-Net observations report
  82. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  83. GRB 241002B: Fermi GBM Observation
  84. Fermi trigger No 749735279: Global MASTER-Net observations report
  85. Fermi trigger No 749630753: Global MASTER-Net observations report
  86. Fermi trigger No 749693019: Global MASTER-Net observations report
  87. GRB 241002B: Swift-XRT observations
  88. GRB 241002B: Swift ToO observations
  89. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  90. GRB 241002B: PRIME near-infrared detection
  91. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  92. GRB 241002C: Swift ToO observations
  93. GRB 241001A : SVOM/VT optical detection
  94. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  95. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  96. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  97. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  98. GRB241001A: REM optical/NIR upper limits
  99. GRB 241002A: Swift/UVOT Upper Limits
  100. EP240930a: Liverpool Telescope observations

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