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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 080925: Suzaku WAM observation of the prompt emission
  2. GRB 081001: Swift UVOT Observations
  3. GRB 081001: Swift-XRT position
  4. GRB081001: optical limit from ASH-Centurion
  5. GRB081001: SuperAGILE Localization of a long GRB
  6. GRB080928: redshift retraction
  7. GRB 080928: Watcher observations
  8. GRB 080927: Fermi GBM detection
  9. GRB 080928: VLT redshift
  10. GRB080928: Gemini-South Absorption Redshift
  11. GRB 080928: Swift-XRT refined analysis
  12. GRB 080928: Swift/UVOT observations
  13. GRB 080928, Swift-BAT final refined analysis
  14. GRB 080928: GROND DETECTION
  15. GRB 080928: Enhanced Swift-XRT position
  16. GRB 080928, Swift-BAT initial refined analysis
  17. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
  18. GRB 080928: Swift detection of a burst with an optical counterpart
  19. GRB 080925: Fermi GBM Detection
  20. GRB 080920: Fermi GBM detection
  21. GRB080922, optical upper limit
  22. Swift-BAT trigger 325707 is not a GRB
  23. Swift trigger 325707: Swift/UVOT Upper Limits
  24. Swift trigger 325707: Swift-XRT upper limit
  25. Swift detection of a possible GRB (trigger 325707)
  26. GRB080916A: Suzaku WAM observation of the prompt emission
  27. GRB 080922: Swift/UVOT Upper Limits
  28. GRB080922: Swift-XRT upper limit
  29. GRB080922: A long GRB detected by INTEGRAL
  30. GRB 080913B: Fermi GBM detection
  31. Trigger 324561: IGR J08408-4503 detected by Swift
  32. GRB 080916C: Fermi GBM Spectral Analysis
  33. GRB 080919: Swift/UVOT Refined Analysis
  34. GRB 080919: Swift-XRT refined analysis
  35. GRB 080919, Swift-BAT refined analysis
  36. GRB 080916C: IRSF/SIRUS NIR Observation
  37. GRB 080916C: GROND Confirmation of the Optical Afterglow
  38. GRB 080916C: GROND Confirmation of the Optical Afterglow
  39. GRB 080919: REM NIR observations
  40. GRB 080919: Swift detection of a short burst
  41. Fermi/GBM Data Now Available
  42. GRB 080915A: GROND upper limits
  43. GRB080913: Swift-BAT spectral lag
  44. GRB 080916A: GROND lightcurve
  45. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  46. GRB 080916A: Rapid PROMPT Observations
  47. GRB 080916A: Fermi GBM detection
  48. GRB 080916C: Swift UVOT Refined Analysis
  49. GRB 080916C: Swift XRT refined analysis
  50. GRB 080916B: Swift-XRT refined analysis
  51. Konus-Wind observation of GRB 080916A
  52. Konus-Wind observation of GRB 080916C
  53. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  54. GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
  55. GRB 080916C: Enhanced XRT position
  56. GRB080916A: Spectroscopic redshift
  57. GRB 080916C: Swift/XRT detection of possible afterglow
  58. GRB 080916B: Swift UVOT Refined Analysis
  59. IPN Triangulation and Energy Spectrum of GRB080916C
  60. GRB 080916B, Swift-BAT refined analysis
  61. GRB080916A: Refined Swift/UVOT Observations
  62. GRB 080915a, SMARTS optical/IR observations
  63. GRB 080916B: Enhanced Swift-XRT position
  64. GRB 080916C: Fermi LAT observation
  65. GRB 080916C: Fermi GBM Detection
  66. GRB 080916A: Swift XRT refined analysis
  67. GRB 080916A, Swift-BAT refined analysis
  68. GRB 080916B: Swift-XRT afterglow detection
  69. GRB 080916A: Enhanced Swift-XRT position
  70. GRB 080916B: Swift detection of a burst
  71. GRB 080916: REM detection of the NIR afterglow
  72. GRB 080916: REM candidate afterglow
  73. GRB 080916: Swift detection of a burst with optical afterglow
  74. GRB 080915B, Swift-BAT refined analysis
  75. GRB 080912 : Fermi GBM detection
  76. GRB 080915B: Swift detection of a burst
  77. GRB 080915: REM NIR early observations
  78. GRB 080915: Swift/UVOT Upper Limits
  79. GRB 080915: Swift-XRT afterglow detection and analysis
  80. GRB 080915, Swift-BAT refined analysis
  81. SGR 0501+4516 : P200 i-band observations
  82. GRB 080915: ROTSE-III Optical Limits
  83. GRB 080915: Swift detection of a burst
  84. GRB 080913: Swift-XRT refined analysis
  85. GRB 080913: VLT/FORS spectrum
  86. GRB080913: Swift/UVOT Upper Limits
  87. GRB 080913: GROND photo-z
  88. GRB 080913, Swift-BAT refined analysis
  89. GRB 080913: VLT/FORS2 observations
  90. GRB 080913: REM NIR early observations
  91. GRB 080913: Enhanced Swift-XRT position
  92. GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
  93. GRB 080913: Swift detection of a burst
  94. GRB 080906: Watcher observations
  95. Swift-BAT/-XRT refined analysis on trigger 324362 (LS I +61 303)
  96. GRB 080906B: Fermi GBM detection
  97. GRB 080905C: Fermi GBM detection
  98. SGR J0501+4516: radio pulsar searches with GBT and WSRT
  99. Swift trigger 324362 (LS I +61 303 ?): XRT
  100. GRB 080905B: Photometric Redshift for the 2MASS Galaxy

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