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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 080915A: GROND upper limits
  2. GRB080913: Swift-BAT spectral lag
  3. GRB 080916A: GROND lightcurve
  4. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  5. GRB 080916A: Rapid PROMPT Observations
  6. GRB 080916A: Fermi GBM detection
  7. GRB 080916C: Swift UVOT Refined Analysis
  8. GRB 080916C: Swift XRT refined analysis
  9. GRB 080916B: Swift-XRT refined analysis
  10. Konus-Wind observation of GRB 080916A
  11. Konus-Wind observation of GRB 080916C
  12. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  13. GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
  14. GRB 080916C: Enhanced XRT position
  15. GRB080916A: Spectroscopic redshift
  16. GRB 080916C: Swift/XRT detection of possible afterglow
  17. GRB 080916B: Swift UVOT Refined Analysis
  18. IPN Triangulation and Energy Spectrum of GRB080916C
  19. GRB 080916B, Swift-BAT refined analysis
  20. GRB080916A: Refined Swift/UVOT Observations
  21. GRB 080915a, SMARTS optical/IR observations
  22. GRB 080916B: Enhanced Swift-XRT position
  23. GRB 080916C: Fermi LAT observation
  24. GRB 080916C: Fermi GBM Detection
  25. GRB 080916A: Swift XRT refined analysis
  26. GRB 080916A, Swift-BAT refined analysis
  27. GRB 080916B: Swift-XRT afterglow detection
  28. GRB 080916A: Enhanced Swift-XRT position
  29. GRB 080916B: Swift detection of a burst
  30. GRB 080916: REM detection of the NIR afterglow
  31. GRB 080916: REM candidate afterglow
  32. GRB 080916: Swift detection of a burst with optical afterglow
  33. GRB 080915B, Swift-BAT refined analysis
  34. GRB 080912 : Fermi GBM detection
  35. GRB 080915B: Swift detection of a burst
  36. GRB 080915: REM NIR early observations
  37. GRB 080915: Swift/UVOT Upper Limits
  38. GRB 080915: Swift-XRT afterglow detection and analysis
  39. GRB 080915, Swift-BAT refined analysis
  40. SGR 0501+4516 : P200 i-band observations
  41. GRB 080915: ROTSE-III Optical Limits
  42. GRB 080915: Swift detection of a burst
  43. GRB 080913: Swift-XRT refined analysis
  44. GRB 080913: VLT/FORS spectrum
  45. GRB080913: Swift/UVOT Upper Limits
  46. GRB 080913: GROND photo-z
  47. GRB 080913, Swift-BAT refined analysis
  48. GRB 080913: VLT/FORS2 observations
  49. GRB 080913: REM NIR early observations
  50. GRB 080913: Enhanced Swift-XRT position
  51. GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
  52. GRB 080913: Swift detection of a burst
  53. GRB 080906: Watcher observations
  54. Swift-BAT/-XRT refined analysis on trigger 324362 (LS I +61 303)
  55. GRB 080906B: Fermi GBM detection
  56. GRB 080905C: Fermi GBM detection
  57. SGR J0501+4516: radio pulsar searches with GBT and WSRT
  58. Swift trigger 324362 (LS I +61 303 ?): XRT
  59. GRB 080905B: Photometric Redshift for the 2MASS Galaxy
  60. Swift trigger 324362 (LS I +61 303 ?)
  61. GRB080905A: Swift/UVOT Upper Limits
  62. GRB 080905B: Watcher optical detection
  63. GRB 080904: Fermi Gamma-ray Burst Monitor detection
  64. GRB 080905B: Fermi Gamma-ray Burst Monitor detection
  65. GRB 080905A: Fermi Gamma-ray Burst Monitor detection
  66. GRB 080905A: Enhanced Swift-XRT position
  67. GRB 080905A: MITSuME Akeno optical upper limits
  68. Swift Trigger 324122 is again known source Swift J1842.5-1124
  69. Swift Trigger 324116 is known source again
  70. Swift Trigger 324112 is known source Swift J1842.5-1124
  71. GRB 080906: Refined Swift/UVOT Observations
  72. GRB 080906: Swift-XRT Refined Analysis
  73. GRB 080906, Swift-BAT refined analysis
  74. GRB 080905A: optical afterglow
  75. GRB 080906: GROND observations of the optical/NIR afterglow
  76. GRB 080905B: Swift-XRT Refined Analysis
  77. GRB 080905B: Refined UVOT Analysis
  78. GRB 080905B: VLT redshift
  79. GRB 080905A: NOT and VLT observations
  80. GRB 080905B: Enhanced Swift-XRT position
  81. GRB 080905B, Swift-BAT refined analysis
  82. GRB 080905A, Swift-BAT refined analysis
  83. GRB 080906: Swift detection of a burst with optical afterglow
  84. GRB 080905A: Swift-XRT Refined Analysis
  85. GRB 080825C: Fermi GBM Spectral Analysis
  86. GRB080825C: Fermi-LAT observations
  87. GRB 080905B: Swift detection of a burst with possible optical counterpart
  88. GRB 080905: R & I-band optical observations
  89. GRB 080905: Swift detection of a probably-short burst
  90. GRB 080903: Swift/UVOT Observations
  91. GRB 080903: Swift-XRT Refined Analysis
  92. GRB 080903: Enhanced Swift-XRT position
  93. GRB 080903, Swift-BAT refined analysis
  94. GRB 080903: optical observations
  95. GRB 080903: Liverpool Telescope observations
  96. GRB 080903: Astrotel-Caucasus optical observations
  97. GRB 080903: Optical afterglow candidate
  98. GRB 080903: TAROT Calern observatory optical observations
  99. GRB 080903: ROTSE-III Optical Limits
  100. GRB 080903: Swift detection of a burst

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