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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

3872 results found.

  1. Fermi GRB 240421B: Global MASTER-Net observations report
  2. GRB 240421B: Fermi GBM Observation
  3. LIGO/Virgo/KAGRA S240421ar: Identification of a GW unmodeled transient candidate
  4. Fermi trigger No 735280430: Global MASTER-Net observations report
  5. GRB 240411A: GOTO early optical upper limits
  6. Fermi GRB 240417A: Global MASTER-Net observations report
  7. Fermi GRB 240415A: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
  9. IPN triangulation of GRB 240410A
  10. IPN triangulation of GRB 240411A
  11. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  12. Fermi GRB 240407A: Global MASTER-Net observations report
  13. GRB 240402C: Glowbug gamma-ray detection
  14. GRB 240402C: GRBAlpha detection
  15. Fermi GRB 240402A: Global MASTER-Net observations report
  16. GRB 240329A: Glowbug gamma-ray detection
  17. GRB 240329A: AstroSat CZTI detection
  18. GRB 240329A: GRBAlpha detection
  19. Fermi trigger No 733366352: Global MASTER-Net observations report
  20. Fermi GRB 240329A: Global MASTER-Net observations report
  21. GRB 240329A: BALROG localization (Fermi Trigger 733441392 / GRB 240329905)
  22. GRB 240329A: Fermi GBM Final Real-time Localization
  23. Fermi GRB 240328B: Global MASTER-Net observations report
  24. Fermi GRB 240328A: Global MASTER-Net observations report
  25. GRB 240320A: Glowbug gamma-ray detection
  26. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  27. Fermi trigger No 732657380: Global MASTER-Net observations report
  28. GRB 240320A: Fermi GBM Final Real-time Localization
  29. Fermi GRB 240318A: Global MASTER-Net observations report
  30. Fermi GRB 240317B: Global MASTER-Net observations report
  31. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  32. Fermi trigger No 732299243: Global MASTER-Net observations report
  33. GRB 240315A: Fermi GBM Final Real-time Localization
  34. Fermi trigger No 731839490: Global MASTER-Net observations report
  35. Fermi GRB 240310A: Global MASTER-Net observations report
  36. GRB 240309A: MAXI/GSC detection
  37. GRID detection of GRB 240229A (Updated Report)
  38. GRID detection of GRB 240229A
  39. GRB 240229A: Glowbug gamma-ray detection
  40. GRB 240229A: GRBAlpha detection
  41. Fermi-LAT gamma-ray observations of IceCube-240229A
  42. GRB 240305C: AstroSat CZTI detection of a short burst
  43. GRB 240229A: VZLUSAT-2 detection
  44. Fermi trigger No 731161136: Global MASTER-Net observations report
  45. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  46. GRB 240229A: CALET Gamma-Ray Burst Monitor detection
  47. IceCube-240229A - IceCube observation of a high-energy neutrino candidate track-like event
  48. GRB 240225B: further SAO RAS optical observations
  49. Fermi GRB 240229A: Global MASTER-Net observations report
  50. IceCube Alert 240229.66: Global MASTER-Net observations report
  51. GRB 240229A: BALROG localization (Fermi Trigger 730908432 / GRB 240229588)
  52. GRB 240229A: Fermi GBM Final Real-time Localization
  53. GRB 240225B: VLT/X-shooter redshift
  54. GRB 240225B: 3.6m DOT observation
  55. GRB 240225B: MAXI/GSC detection
  56. Transient EPW20240219aa: Mondy optical observations
  57. Fermi trigger No 729914426: Global MASTER-Net observations report
  58. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  59. Fermi trigger No 729650855: Global MASTER-Net observations report
  60. Fermi GRB 240213A: Global MASTER-Net observations report
  61. Fermi trigger No 729152364: Global MASTER-Net observations report
  62. Fermi trigger No 729012023: Global MASTER-Net observations report
  63. GRB 240204A: Mondy optical afterglow observations
  64. Fermi trigger No 728749569: Global MASTER-Net observations report
  65. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  66. Fermi GRB 240204A: Global MASTER-Net observations report
  67. Fermi trigger No 728706420: Global MASTER-Net observations report
  68. IceCube Alert 240204.38: Global MASTER-Net observations report
  69. GRB 240129A: Fermi GBM Observation
  70. Fermi GRB 240127A: Global MASTER-Net observations report
  71. Konus-Wind detection of GRB 240119A (short/hard)
  72. IPN triangulation of GRB 240119A (short)
  73. GRB 240119A: GECAM detection of a short burst
  74. GRB 240119A: AstroSat CZTI detection of a short burst
  75. GRB 240118A: Mondy optical observations
  76. GRB 240119A: Fermi GBM Final Localization
  77. GRID detection of GRB 231230A
  78. IPN triangulation of GRB 240112A (long)
  79. GRB 240112C: Swift/UVOT Detection
  80. Fermi trigger No 726773850: Global MASTER-Net observations report
  81. GRB 240112C: Swift-XRT refined Analysis
  82. Fermi trigger No 726774492: Global MASTER-Net observations report
  83. GRB 240112C: Swift detection of a burst with an optical counterpart
  84. GRB 240112A: GECAM detection of a burst
  85. GRB 230812B: further radio observations with the VLA
  86. GRB 240107A: MAXI/GSC detection
  87. LIGO/Virgo/KAGRA S240107b: Identification of a GW compact binary merger candidate
  88. IceCube-Cascade 231230A: Upper limits from a search for additional neutrino events in IceCube
  89. Fermi trigger No 725806648: Global MASTER-Net observations report
  90. GRB231230A: Fermi GBM Observation
  91. Fermi trigger No 725592555: Global MASTER-Net observations report
  92. GRB 231230A: Swift detection of a burst
  93. GRB 231230A: Fermi GBM Final Real-time Localization
  94. Fermi trigger No 724781422: Global MASTER-Net observations report
  95. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  96. GRB 231205B: VZLUSAT-2 detection
  97. Konus-Wind detection of GRB 231210B
  98. Swift GRB231215.41: Global MASTER-Net observations report
  99. Fermi trigger No 724278269: Global MASTER-Net observations report
  100. GRB 231210B: Swift detection of a burst with optical counterpart

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