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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 110604A Detection by IPN Spacecraft and Swift-BAT
  2. GRB 110530A: optical observations in Mondy observatory
  3. GRB 110529A: Suzaku WAM observation of the prompt emission
  4. GMRT detection of GRB 110328A
  5. GRB 110530A: optical observations at Mt. Terskol, second epoch
  6. GRB 110530A: Swift-XRT refined Analysis
  7. GRB 110530A: Swift/UVOT Detection of a Fading Afterglow
  8. GRB 110530A: Xinglong TNT observation
  9. GRB 110530A: Enhanced Swift-XRT position
  10. GRB 110530A: NOT optical observations
  11. GRB110530A: MITSuME Okayama Optical Observation
  12. GRB 110530A: optical observations at Mt. Terskol
  13. GRB 110530A: Correction to GCN Circ 12050
  14. GRB 110530A: MASTER OT observations
  15. GRB 110530A: Swift-BAT refined analysis
  16. GRB 110530A: MITSuME Akeno Optical Observation
  17. GRB 110529A: Fermi GBM detection
  18. GRB 110530A: Swift detection of a burst with an optical afterglow
  19. Konus-Wind observation of GRB 110529A
  20. LAT Observations of GRB110529A
  21. EVLA afterglow limits on the high z GRB090429B
  22. Fermi Gamma-ray Burst Monitor trigger 328195911 is not a GRB
  23. Swift J1644+57/GRB 110328A, Additional HST Observations
  24. GRB 110521A: MASTER prompt optical limit
  25. GRB 110521A: Swift/UVOT Upper Limits
  26. GRB 110521A: Swift-XRT refined analysis
  27. GRB 110520A: NOT optical follow-ups
  28. GRB 110521A - NOT optical observation
  29. GRB 110521A: Swift-BAT refined analysis
  30. GRB 110521A: Enhanced Swift-XRT position
  31. GRB 110521A: MASTER synchronous and early optical observations limit
  32. Swift/UVOT observations of GRB110520A
  33. GRB 110521A: Swift detection of a burst
  34. GRB 110520A: Swift-BAT refined analysis
  35. GRB 110520A: IAC80 I-band observations
  36. GRB 110520A: Swift-XRT refined Analysis
  37. GRB 110520A: Enhanced Swift-XRT position
  38. GRB 110520A: WHT IR observations
  39. GRB 110520A - NOT optical observation
  40. GRB 110520A: Skynet/DAO optical observations
  41. GRB 110520A: Liverpool Telescope Observations
  42. GRB 110520A: TAROT Calern observatory optical observations
  43. GRB 110520A: MASTER-NET optical observations
  44. GRB 110520A: Swift detection of a burst
  45. Konus-Wind observation of GRB 110518A
  46. IPN localization of bright GRB 110518A
  47. Radio observations of GRB 110428A with the EVLA
  48. GRB 110519A, Swift-BAT refined analysis
  49. GRB 110519A: Swift detection of a burst
  50. GRB 110503A optical observation
  51. GRB 110426A: Fermi GBM detection
  52. GRB 110428A: Fermi-GBM observation
  53. GRB 110503A: TAROT Calern observatory optical observations
  54. GRB 110503A: Jet Break seen from TLS
  55. GRB 110503A optical observations
  56. Konus-Wind observation of GRB 110503A
  57. GRB 110422A: MASTER first 30 min OT light curve
  58. GRB 110422A: Herschel FIR observation preliminary report
  59. GRB 110503A: optical observation in CrAO
  60. GRB 110503A: R-band Detection
  61. GRB 110503A: Centimeter observation from EVLA
  62. GRB 110503A: Millimeter observation from SMA
  63. GRB 110503A: SARA-N Observations and Photometric Calibration
  64. GRB 110503A: Swift/UVOT Observations
  65. GRB 110503A: Swift-XRT refined Analysis
  66. GRB 110503A: PAIRITEL NIR Detection
  67. GRB 110503A: redshift confirmation from TNG
  68. GRB 110503A - TLS Afterglow Observations
  69. GRB 110503A: Swift-BAT refined analysis
  70. GRB 110503A: NOT afterglow photometry
  71. GRB 110503A: Redshift from 10.4m GTC
  72. GRB 110503A: Enhanced Swift-XRT position
  73. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  74. GRB 110426A: Swift/XRT non-detection
  75. GRB 110428A : X-ray afterglow confirmation
  76. GRB 110428A: Suzaku WAM observation of the prompt emission
  77. Fermi-GBM data processing and delivery
  78. GRB 110422A: optical observations in CrAO
  79. GRB 110422A: Update of Herschel FIR observation schedule
  80. GRB 110428A : Swift-XRT observations
  81. Konus-Wind observation of GRB 110428A
  82. GRB 110428A: Fermi-LAT Detection
  83. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  84. GRB 110426A: MAXI/GSC detection of a GRB
  85. GRB 110422A: optical observations in CrAO, second epoch
  86. GRB 110422A: Redshift confirmation from GTC
  87. GRB 110422A: tentative redshift from TNG
  88. GRB 110422A: Suzaku WAM observation of the prompt emission
  89. GRB 110422A: Herschel observation scheduled
  90. GRB110422A: NOT optical follow-ups
  91. GRB 110422A: optical observations in CrAO
  92. GRB110422A: MITSuME Ishigakijima Optical Observation
  93. Konus-Wind observation of GRB 110422A
  94. GRB 110422A: Further NOT observation
  95. GRB 110422A: Swift/UVOT Detection of optical afterglow
  96. GRB 110422A: Swift-XRT refined Analysis
  97. GRB 110422A: CQUEAN griz Observation
  98. GRB 110422A: THO optical observations
  99. GRB 110422A: Enhanced Swift-XRT position
  100. GRB 110422A: correction to the GCN circ. 11958

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