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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"

32763 results found.

  1. GRB 240523A: Swift-BAT refined analysis
  2. LIGO/Virgo/KAGRA S240525p: Updated Sky localization
  3. LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
  4. GRB 240521B: Fermi GBM Observation
  5. Fermi GBM Sub-Threshold Detection of GRB 240516B
  6. GRB 240513A: Swift-XRT afterglow detection
  7. LIGO/Virgo/KAGRA S240520cv: Updated Sky localization and EM Bright Classification
  8. EP240518a: GSP optical upper limit
  9. LIGO/Virgo/KAGRA S240520cv: Identification of a GW compact binary merger candidate
  10. GRB 240514B: VZLUSAT-2 detection
  11. GRB 240504A: VZLUSAT-2 detection
  12. GRB 240502A: VZLUSAT-2 detection
  13. GRB 240519A: GRBAlpha detection
  14. GRB 240516A: Swift/UVOT Upper Limits
  15. GRB 240519A: AstroSat CZTI detection
  16. EP240518a: possibly identified with a flare star by EP-FXT
  17. LIGO/Virgo/KAGRA S240514c: Updated Sky localization
  18. GRB 240516A: Swift-BAT refined analysis
  19. Fermi GRB 240517A: Global MASTER-Net observations report
  20. GRB 240516A ATCA radio observations
  21. IPN triangulation of GRB 240514B (short)
  22. GRB 240513A: Swift ToO observations
  23. Konus-Wind detection of GRB 240513A
  24. GRB 240516A: AstroSat CZTI detection
  25. GRB 240516A: Swift-XRT refined Analysis
  26. GRB 240514E: A possible candidate BD-21 1074
  27. GRB 240516A: Fermi GBM Observation
  28. GRB 240511A: Observations from GTC/OSIRIS+
  29. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  30. GRB 240516A: GOTO optical upper limit
  31. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  32. GRB 240511A: radio detection of afterglow candidate
  33. GRB 240514B: GOTO candidate optical counterpart
  34. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  35. GRB 240514B: GRBAlpha detection
  36. LIGO/Virgo/KAGRA S240514x: Updated Sky localization
  37. LIGO/Virgo/KAGRA S240515m: Identification of a GW compact binary merger candidate
  38. GRB 240514B: Fermi GBM Detection
  39. GRB 240513A: Fermi GBM observation
  40. LIGO/Virgo/KAGRA S240513ei: Updated Sky localization
  41. LIGO/Virgo/KAGRA S240514x: Identification of a GW compact binary merger candidate
  42. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
  43. Fermi GRB 240514B: Global MASTER-Net observations report
  44. GRB 240513A: Tiled Swift observations
  45. GRB 240513A: Fermi-LAT detection
  46. LIGO/Virgo/KAGRA S240513ei: Identification of a GW compact binary merger candidate
  47. GRB 240511A: Fermi GBM Observation
  48. GRB 240511A: Swift-BAT refined analysis
  49. Fermi GRB 240513B: Global MASTER-Net observations report
  50. GRB 240511A: J-band observations with WINTER
  51. GRB 240511A : MITSuME Akeno optical upper limits
  52. LIGO/Virgo/KAGRA S240512r: Updated Sky localization and EM Bright Classification
  53. GRB 240511A: optical afterglow detection from the NOT
  54. LIGO/Virgo/KAGRA S240512r: Identification of a GW compact binary merger candidate
  55. Fermi GRB 240511A: Global MASTER-Net observations report
  56. Swift GRB 240511A: Global MASTER-Net observations report
  57. LIGO/Virgo/KAGRA S240511i: Updated Sky localization
  58. LIGO/Virgo/KAGRA S240511i: Identification of a GW compact binary merger candidate
  59. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  60. LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
  61. EP240506a: Xinglong optical upper limit
  62. EP240506a: CrAO ZTSH optical upper limit
  63. GRB 240504A: Fermi GBM Observation
  64. EP240506a: Archival radio searching
  65. EP240506a: TRT optical upper limit
  66. LIGO/Virgo/KAGRA S240507p: Updated Sky localization and EM Bright Classification
  67. EP240506a: Optical upper limit with Kinder observations
  68. IPN triangulation of GRB 240504A
  69. GRB 240502A: 1.3m DFOT Optical upper limit
  70. LIGO/Virgo/KAGRA S240507p: Identification of a GW compact binary merger candidate
  71. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  72. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfr and AT2024hfs
  73. LIGO/Virgo/KAGRA S240505av: Updated Sky localization and EM Bright Classification
  74. LIGO/Virgo/KAGRA S240505av: Identification of a GW compact binary merger candidate
  75. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  76. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  77. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  78. Fermi GRB 240504A: Global MASTER-Net observations report
  79. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  80. GRB 240502A: GOTO optical upper limit
  81. GRB 240502A: Fermi GBM Observation
  82. GRB 240415A 1.3m DFOT Optical upper limit
  83. GRB 240502C: GOTO possible optical counterpart candidates
  84. LIGO/Virgo/KAGRA S240501an: Updated Sky localization and EM Bright Classification
  85. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
  86. Fermi GRB 240502B: Global MASTER-Net observations report
  87. Fermi GRB 240502A: Global MASTER-Net observations report
  88. GRB 240501B: GRBAlpha detection
  89. GRB 240430A: GRBAlpha detection
  90. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  91. LIGO/Virgo/KAGRA S240422ed: Host redshifts of AT2024hfq, AT2024hfu, and AT2024hmo from DBSP
  92. Fermi GRB 240501A: Global MASTER-Net observations report
  93. GRB 240426A: VZLUSAT-2 detection
  94. GRB 240425A: VZLUSAT-2 detection
  95. MeerKAT Discovery of a Probable Radio Counterpart to EP240414a
  96. GRB 240408B: VZLUSAT-2 detection
  97. GRB 240407A: VZLUSAT-2 detection
  98. LIGO/Virgo/KAGRA S240501an: Identification of a GW compact binary merger candidate
  99. X-ray transient EP240414a: Detection of associated supernova
  100. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification

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