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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"

28053 results found.

  1. GRB 110428A: Fermi-GBM observation
  2. GRB 110503A: TAROT Calern observatory optical observations
  3. Konus-Wind observation of GRB 110503A
  4. GRB 110503A: optical observation in CrAO
  5. GRB 110503A: Centimeter observation from EVLA
  6. GRB 110503A: Millimeter observation from SMA
  7. GRB 110503A: SARA-N Observations and Photometric Calibration
  8. GRB 110503A: Swift/UVOT Observations
  9. GRB 110503A: Swift-XRT refined Analysis
  10. GRB 110503A: PAIRITEL NIR Detection
  11. GRB 110503A: Swift-BAT refined analysis
  12. GRB 110503A: Enhanced Swift-XRT position
  13. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  14. GRB 110426A: Swift/XRT non-detection
  15. GRB 110428A : X-ray afterglow confirmation
  16. GRB 110428A: Suzaku WAM observation of the prompt emission
  17. GRB 110422A: optical observations in CrAO
  18. GRB 110428A : Swift-XRT observations
  19. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  20. GRB 110422A: optical observations in CrAO, second epoch
  21. GRB 110422A: Suzaku WAM observation of the prompt emission
  22. GRB110422A: NOT optical follow-ups
  23. GRB 110422A: optical observations in CrAO
  24. GRB110422A: MITSuME Ishigakijima Optical Observation
  25. GRB 110422A: Further NOT observation
  26. GRB 110422A: Swift/UVOT Detection of optical afterglow
  27. GRB 110422A: Swift-XRT refined Analysis
  28. GRB 110422A: Enhanced Swift-XRT position
  29. GRB 110422A: TNG optical observations
  30. GRB 110422A: SAO RAS optical observations
  31. GRB 110422A: NOT optical observation
  32. GRB 110422A: Swift-BAT refined analysis
  33. GRB 110422A: Mondy optical observations
  34. GRB 110422A: Swift detection of a burst
  35. GRB 110420B: Swift/UVOT Upper Limits
  36. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  37. GRB 110420B: Swift-XRT afterglow candidate retraction
  38. GRB 110420B, GROND observations
  39. GRB 110420A Swift/UVOT Observations
  40. GRB 110420B: Swift-XRT afterglow candidate
  41. GRB 110420B: Swift-BAT refined analysis
  42. GRB 110420A: Swift-BAT refined analysis
  43. GRB 110420A: Swift-XRT refined Analysis
  44. GRB 110420A: Enhanced Swift-XRT position
  45. GRB 110420A: Swift detection of a burst with optical counterpart
  46. GRB110414A: MITSuME Ishigakijima Optical upper limits
  47. GRB 110414A: GROND upper limits
  48. GRB110414A: MITSuME Okayama Optical upper limits
  49. GRB 110414A: Swift-BAT Refined Analysis
  50. GRB 110414A: Swift/UVOT Upper limits
  51. GRB 110414A: Swift-XRT refined Analysis
  52. GRB 110414A: Enhanced Swift-XRT position
  53. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  54. GRB 110414A : Faulkes Telescope North observations
  55. GRB 110414A: Swift detection of a burst
  56. GRB 110411A: PAIRITEL NIR Upper Limits
  57. GRB 110412A: Swift-BAT refined analysis
  58. GRB 110411A: Swift-XRT refined Analysis
  59. GRB 110411A: Swift/UVOT Upper Limits
  60. GRB 110411A : Xinglong TNT OT candidate
  61. GRB 110411A, Swift-BAT refined analysis
  62. GRB 110411A: Enhanced Swift-XRT position
  63. GRB 110411A: Swift detection of a burst
  64. GRB 110407A: Swift-XRT refined Analysis
  65. GRB 110328A / Swift J164449.3+573451: MASTER pre, prompt and follow-up observations
  66. GRB 110328A / Swift J164449.3+573451: optical observations
  67. GRB 110328A/Swift J164449.3+573451 UVOT Upper Limits
  68. GRB 110406A: Positional coincidence with NGC 404
  69. GRB110407A: UVOT Upper Limits
  70. GRB 110407A: GROND Detection of the Optical Afterglow
  71. GRB 110407A: MITSuME Okayama and Ishigakijima Optical upper limits
  72. GRB 110407A: NOT optical observations
  73. GRB 110407A: Enhanced Swift-XRT position
  74. GRB 110407A: Swift-BAT refined analysis
  75. GRB 100407A : Errata of afterglow position in GCN 11899
  76. IPN triangulation of the bright GRB110406A
  77. GRB 110407A : Lulin optical afterglow detection
  78. GRB 110407A: Swift detection of a burst
  79. Konus-Wind observation of GRB 110406A
  80. GRB 110328A/Swift J164449.3+573451: BAT recent rate increase and pre-outburst,light curve
  81. GRB 110402A: fading optical afterglow
  82. GRB 110402A: Suzaku WAM observation of the prompt emission
  83. GRB 110402A: LOAO Optical Observation
  84. GRB 110328A / Swift J164449.3+573451, HST Observations
  85. GRB 110402A: Konus-Wind spectral lags and detailed energetics
  86. GRB 110401A: Fermi GBM detection
  87. GRB 110402A: Fermi GBM detection
  88. GRB 110402A: optical observations in Mondy
  89. GRB 110402A afterglow observation
  90. GRB 110328A / Swift J164449.3+573451: Keck/DEIMOS Optical Spectroscopy
  91. GRB 110402A: MITSuME Okayama and Ishigakijima Optical upper limits
  92. GRB 110328A/Swift J164449.3+573451: SARA-N detection
  93. GRB 110402A: Swift/UVOT detection of afterglow candidate
  94. GRB 110402A: Konkoly observations
  95. GRB 110328A: Konkoly observations.
  96. GRB 110402A: Swift-BAT refined analysis
  97. GRB 110402A: Swift-XRT refined Analysis
  98. GRB 110402A: early optical limit by "Pi of the Sky"
  99. GRB 110402A: further NOT observations
  100. GRB110328A/Swift J164449.3+573451: Fermi LAT Observations

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