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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"

22096 results found.

  1. EP241021a: TRT optical observations
  2. GRB 241018A: SVOM/C-GFT optical observations
  3. EP241021a: NOT likely optical counterpart
  4. EP EP241021a: Global MASTER-Net observations report
  5. GRB241017A: 1.3m DFOT optical upper limit
  6. GRB 241018A: 1.3m DFOT Optical upper limit
  7. EP241021a: GOTO optical upper limits
  8. EP241021a: EP detection of a fast X-ray transient
  9. GRB 241017A/sb24101702: Mephisto optical upper limit
  10. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  11. GRB 241018A: GROWTH-India telescope optical upper limit
  12. GRB 241018A: Swift-XRT observations
  13. GRB 241018A: REM optical/NIR upper limits
  14. GRB 241018A: NOT optical observations
  15. GRB 241017A: SVOM/VT follow-up and optical upper limit
  16. GRB 241018A: SVOM/VT follow-up and optical candidate
  17. GRB 241018A: Swift ToO observations
  18. GRB 241018A: X-ray afterglow candidate observed by MXT
  19. GRB 241016B: Fermi GBM Observations
  20. GRB 241017A: Swift-XRT observations
  21. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  22. GRB241017A: TOO Observations by SVOM/MXT
  23. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  24. GRB 241017A: J-band upper limit from WINTER
  25. Fermi trigger No 750788395: Global MASTER-Net observations report
  26. GRB 241017A: Swift ToO observations
  27. Fermi GRB 241016B: Global MASTER-Net observations report
  28. Fermi GRB 241016A: Global MASTER-Net observations report
  29. IceCube Alert 241016.04: Global MASTER-Net observations report
  30. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  31. GRB 240916A: radio detection with the VLA
  32. GRB241013A: REM observations
  33. Fermi GRB 241013B: Global MASTER-Net observations report
  34. Integral GRB241013.04: Global MASTER-Net observations report
  35. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  36. GRB 241009A: GRANDMA optical upper limits
  37. GRB 241009A: Swift-XRT afterglow detection
  38. GRB 241010A: JinShan optical observations and potential host galaxy
  39. GRB 241006A: ATCA Radio Upper Limits
  40. Fermi trigger No 750211959: Global MASTER-Net observations report
  41. Swift GRB 241010A: Global MASTER-Net observations report
  42. Fermi trigger No 750291012: Global MASTER-Net observations report
  43. GRB 241010A: J-band observations with WINTER
  44. Fermi GRB 241010B: Global MASTER-Net observations report
  45. GRB 241010A: LCO optical observations
  46. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  47. GRB 241009A: Swift ToO observations
  48. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  49. GRB 241002B: Swift-XRT afterglow detection
  50. GRB 241002A: NOT optical upper limits
  51. Fermi GRB 241008A: Global MASTER-Net observations report
  52. IceCube-241006A: No candidates from the Zwicky Transient Facility
  53. GRB 241006A: GRANDMA optical upper limits
  54. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  55. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  56. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  57. GRB 240910A: LBT optical observations
  58. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  59. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  60. GRB 241006A: PRIME near-infrared upper limits
  61. GRB 241006A: Swift/UVOT Upper Limits
  62. GRB 241006A: SVOM/VT follow-up and optical upper limit
  63. IceCube Alert 241006.94: Global MASTER-Net observations report
  64. GRB 241001A: Swift-XRT afterglow detection
  65. Swift GRB241006.91: Global MASTER-Net observations report
  66. Fermi trigger No 749721670: Global MASTER-Net observations report
  67. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  68. GRB 241002B: Fermi GBM Observation
  69. Fermi trigger No 749735279: Global MASTER-Net observations report
  70. Fermi trigger No 749630753: Global MASTER-Net observations report
  71. Fermi trigger No 749693019: Global MASTER-Net observations report
  72. GRB 241002B: Swift-XRT observations
  73. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  74. GRB 241002B: Swift ToO observations
  75. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  76. Konus-Wind detection of GRB 240926A
  77. GRB 241002B: PRIME near-infrared detection
  78. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  79. GRB 241002C: Swift ToO observations
  80. GRB 241001A : SVOM/VT optical detection
  81. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  82. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  83. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  84. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  85. GRB241001A: REM optical/NIR upper limits
  86. GRB 241002A: Swift/UVOT Upper Limits
  87. EP240930a: Liverpool Telescope observations
  88. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  89. GRB 241001A: Swift/UVOT Detection
  90. GRB 241001A: VLT/X-shooter redshift
  91. GRB 241002B: GOTO optical counterpart candidate
  92. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  93. GRB 240929A: Liverpool Telescope prompt followup observations
  94. Fermi GRB 241002B: Global MASTER-Net observations report
  95. GRB 241001A: Swift-XRT observations
  96. GRB241001A: optical afterglow candidate
  97. GRB 241002A: 1.5m OSN optical upper limit
  98. GRB 241001A: Swift ToO observations
  99. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  100. Fermi-LAT Gamma-ray Observations of IceCube-240929A

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