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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"
  1. GRB 150907B: Swift-XRT refined Analysis
  2. Konus-Wind observation of GRB 150906B
  3. IPN Triangulation of GRB 150906B (short/intense)
  4. Fermi GBM trigger 463339482/150907725 is too weak to be classified
  5. GRB 150907B: Swift-BAT refined analysis
  6. GRB150907A: Swift/UVOT observations
  7. GRB 150907B: MASTER-SAAO early optical observations
  8. GRB 150907B: Enhanced Swift-XRT position
  9. GRB 150907B: GROND Upper Limits
  10. GRB 150907B: Swift-XRT observations
  11. GRB 150907A: Swift-XRT observations
  12. GRB 150907B: Swift detection of a burst
  13. Fermi GBM trigger 150907763 is not a GRB
  14. GRB 150907A: Tiled Swift observations
  15. GRB 150907A: MAXI/GSC detection
  16. GRB 150906A: Fermi GBM detection
  17. GRB 150818A: TSHAO and SAO RAS optical observations
  18. GRB 150902A: Swift-XRT afterglow detection
  19. ANTARES neutrino detection: ANU 2.3m and Kepler K2 Observations of the Swift x-ray source
  20. ANTARES neutrino detection: CAHA photometry & spectroscopy of the Swift source
  21. ANTARES neutrino Alert150901.32 alert and Swift XRT counterpart: MASTER optical observations and new possible candidate
  22. ANTARES neutrino detection and Swift/XRT counterpart: GMG observation
  23. GRB 150902A: Swift/UVOT Upper Limits
  24. GRB 150902A: Swift-XRT observations
  25. ANTARES neutrino detection: Optical/NIR spectroscopy of the Swift/XRT counterpart candidate from NOT
  26. GRB 150831A: 9.8 GHz VLA upper limits
  27. GRB 150902A: MASTER-SAAO optical observations
  28. Konus-Wind observation of GRB 150902A
  29. GRB 150901A, Swift-BAT refined analysis
  30. ANTARES neutrino detection and possible Swift X-ray counterpart
  31. GRB 150902A: Swift ToO observations
  32. GRB 150902A: Fermi GBM detection
  33. GRB 150902A: Fermi-LAT detection
  34. GRB 150831B: Swift/UVOT Upper Limits
  35. Konus-Wind observation of GRB 150831A
  36. GRB 150901A: Swift detection of a burst
  37. GRB 150821A: Flattening in the UVOT light curve
  38. GRB 150831B: Swift-BAT refined analysis
  39. GRB 150831B: Swift-XRT refined Analysis
  40. GRB 150831B: MASTER-IAC early optical observations
  41. GRB 150831B: Fermi GBM detection
  42. GRB 150831A: GROND Upper Limits
  43. GRB 150831A: Swift/UVOT Upper Limits
  44. GRB 150831B: Swift-XRT observations
  45. GRB 150831A: Swift-XRT refined Analysis
  46. GRB 150831B: Swift detection of a probable burst
  47. GRB 150831A: Swift-BAT refined analysis
  48. GRB 150818A: Spectroscopic confirmation of the SN from GTC
  49. GRB 150831A: Enhanced Swift-XRT position
  50. GRB 150831A: optical upper limit ISON-SSO
  51. INTEGRAL detection of GRB 150831A
  52. GRB 150831A: Swift detection of a short burst
  53. Fermi GBM trigger 150829183 is not a GRB
  54. Fermi GBM trigger 150828520 is not a GRB
  55. Fermi GBM trigger 150827524 is not a GRB
  56. GRB 150818A: possible SN rise in light curve of Mondy observations
  57. Fermi GBM trigger 150826536 is not a GRB
  58. Konus-Wind observation of GRB 150824A
  59. IPN Triangulation of GRB 150824A
  60. GRB 150824A: Fermi GBM detection
  61. Konus-Wind observation of GRB 150821A
  62. GRB 150821A: LCOGT Siding Springs early observations
  63. Konus-Wind observation of GRB 150818A
  64. GRB 150821A: LCOGT Sutherland observations
  65. GRB 150821A, Swift-BAT refined analysis
  66. GRB 150821A: GROND afterglow observations
  67. GRB 150821A: Swift-XRT refined Analysis
  68. GRB 150819A: Mondy and TSHAO optical upper limits
  69. GRB 150821A: Swift/UVOT Detection
  70. GRB 150821A: Enhanced Swift-XRT position
  71. GRB 150821A: Fermi GBM detection
  72. GRB 150818A: continued Mondy optical observations
  73. Swift Trigger 652824 is due to noise
  74. GRB 150821A: VLT/X-shooter redshift
  75. GRB 150821A: Swift detection of a burst with an optical afterglow
  76. Swift Trigger 652824: Is most likely a noise fluctuation in the direction of M31
  77. GRB 120729A: KAIT Optical Observations
  78. KAIT Optical Upper Limits for GRB 120422A, 120724A, 120803B, 120911A, and 120923A
  79. GRB 150818A: Mondy optical observations
  80. GRB150819A: NOT imaging
  81. Konus-Wind observation of GRB 150819B
  82. GRB 150818A: Continued NOT monitoring - afterglow confirmation
  83. GRB 150819B: Fermi GBM detection
  84. GRB 150818A: 10.4m GTC spectroscopy and host galaxy
  85. IPN Triangulation of GRB 150819B (short / very intense)
  86. GRB 150818A: Mondy optical observations
  87. GRB 150818A: MITSuME Ishigakijima upper limits
  88. GRB 150819A: RATIR Optical Observations
  89. GRB 150819A: Swift-XRT refined Analysis
  90. GRB 150818A: MITSuME Akeno optical upper limits
  91. GRB 150819A: Swift-BAT refined analysis
  92. GRB 150819A: MASTER-IAC early upper limit
  93. GRB 150819A: Swift/UVOT Upper Limits
  94. GRB 150819A: Enhanced Swift-XRT position
  95. GRB 150818A: Swift-XRT update, correction to GCN 18162
  96. GRB 150819A: Prompt enhanced Swift-XRT position
  97. GRB150818A: NOT imaging
  98. GRB 150819A: Swift detection of a burst
  99. GRB 150818A: Swift-XRT refined Analysis
  100. GRB 150818A: Swift/UVOT Detection

Advanced

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