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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 110521A: Swift detection of a burst
  2. GRB 110520A: Swift-BAT refined analysis
  3. GRB 110520A: IAC80 I-band observations
  4. GRB 110520A: Swift-XRT refined Analysis
  5. GRB 110520A: Enhanced Swift-XRT position
  6. GRB 110520A: WHT IR observations
  7. GRB 110520A - NOT optical observation
  8. GRB 110520A: Skynet/DAO optical observations
  9. GRB 110520A: Liverpool Telescope Observations
  10. GRB 110520A: TAROT Calern observatory optical observations
  11. GRB 110520A: MASTER-NET optical observations
  12. GRB 110520A: Swift detection of a burst
  13. Konus-Wind observation of GRB 110518A
  14. IPN localization of bright GRB 110518A
  15. Radio observations of GRB 110428A with the EVLA
  16. GRB 110519A, Swift-BAT refined analysis
  17. GRB 110519A: Swift detection of a burst
  18. GRB 110503A optical observation
  19. GRB 110426A: Fermi GBM detection
  20. GRB 110428A: Fermi-GBM observation
  21. GRB 110503A: TAROT Calern observatory optical observations
  22. GRB 110503A: Jet Break seen from TLS
  23. GRB 110503A optical observations
  24. Konus-Wind observation of GRB 110503A
  25. GRB 110422A: MASTER first 30 min OT light curve
  26. GRB 110422A: Herschel FIR observation preliminary report
  27. GRB 110503A: optical observation in CrAO
  28. GRB 110503A: R-band Detection
  29. GRB 110503A: Centimeter observation from EVLA
  30. GRB 110503A: Millimeter observation from SMA
  31. GRB 110503A: SARA-N Observations and Photometric Calibration
  32. GRB 110503A: Swift/UVOT Observations
  33. GRB 110503A: Swift-XRT refined Analysis
  34. GRB 110503A: PAIRITEL NIR Detection
  35. GRB 110503A: redshift confirmation from TNG
  36. GRB 110503A - TLS Afterglow Observations
  37. GRB 110503A: Swift-BAT refined analysis
  38. GRB 110503A: NOT afterglow photometry
  39. GRB 110503A: Redshift from 10.4m GTC
  40. GRB 110503A: Enhanced Swift-XRT position
  41. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  42. GRB 110426A: Swift/XRT non-detection
  43. GRB 110428A : X-ray afterglow confirmation
  44. GRB 110428A: Suzaku WAM observation of the prompt emission
  45. Fermi-GBM data processing and delivery
  46. GRB 110422A: optical observations in CrAO
  47. GRB 110422A: Update of Herschel FIR observation schedule
  48. GRB 110428A : Swift-XRT observations
  49. Konus-Wind observation of GRB 110428A
  50. GRB 110428A: Fermi-LAT Detection
  51. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  52. GRB 110426A: MAXI/GSC detection of a GRB
  53. GRB 110422A: optical observations in CrAO, second epoch
  54. GRB 110422A: Redshift confirmation from GTC
  55. GRB 110422A: tentative redshift from TNG
  56. GRB 110422A: Suzaku WAM observation of the prompt emission
  57. GRB 110422A: Herschel observation scheduled
  58. GRB110422A: NOT optical follow-ups
  59. GRB 110422A: optical observations in CrAO
  60. GRB110422A: MITSuME Ishigakijima Optical Observation
  61. Konus-Wind observation of GRB 110422A
  62. GRB 110422A: Further NOT observation
  63. GRB 110422A: Swift/UVOT Detection of optical afterglow
  64. GRB 110422A: Swift-XRT refined Analysis
  65. GRB 110422A: CQUEAN griz Observation
  66. GRB 110422A: THO optical observations
  67. GRB 110422A: Enhanced Swift-XRT position
  68. GRB 110422A: correction to the GCN circ. 11958
  69. GRB 110422A: TNG optical observations
  70. GRB 110422A: SAO RAS optical observations
  71. GRB 110422A: NOT optical observation
  72. GRB 110422A: MASTER earlier OT polarization observations
  73. GRB 110422A: Swift-BAT refined analysis
  74. GRB 110422A: Mondy optical observations
  75. GRB 110422A: Swift detection of a burst
  76. GRB 110328A/Swift J164449.3+573451: Maidanak Optical Observation
  77. GRB 110420B: Swift/UVOT Upper Limits
  78. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  79. GRB 110420B: Swift-XRT afterglow candidate retraction
  80. GRB 110420B: Fermi GBM observation
  81. Konus-Wind observation of GRB 110420A
  82. GRB 110420B: Spectral lag indicates short hard burst
  83. GRB 110420B, GROND observations
  84. GRB 110420A Swift/UVOT Observations
  85. GRB 110420B: Swift-XRT afterglow candidate
  86. GRB 110420B: Swift-BAT refined analysis
  87. GRB 110420A: Swift-BAT refined analysis
  88. GRB 110420B: Swift detection of a short hard burst
  89. GRB 110420A: Swift-XRT refined Analysis
  90. GRB 110420A: Enhanced Swift-XRT position
  91. GRB 110420A: Swift detection of a burst with optical counterpart
  92. GRB110414A: MITSuME Ishigakijima Optical upper limits
  93. GRB 110414A: GROND upper limits
  94. GRB110414A: MITSuME Okayama Optical upper limits
  95. GRB 110414A: Swift-BAT Refined Analysis
  96. GRB 110414A: Swift/UVOT Upper limits
  97. GRB 110414A: Swift-XRT refined Analysis
  98. GRB 110414A: Enhanced Swift-XRT position
  99. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  100. GRB 110414A : Faulkes Telescope North observations

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