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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"

42572 results found.

  1. GRB 110520A: Swift-XRT refined Analysis
  2. GRB 110520A: Enhanced Swift-XRT position
  3. GRB 110520A: WHT IR observations
  4. GRB 110520A - NOT optical observation
  5. GRB 110520A: Skynet/DAO optical observations
  6. GRB 110520A: Liverpool Telescope Observations
  7. GRB 110520A: TAROT Calern observatory optical observations
  8. GRB 110520A: MASTER-NET optical observations
  9. GRB 110520A: Swift detection of a burst
  10. Konus-Wind observation of GRB 110518A
  11. IPN localization of bright GRB 110518A
  12. Radio observations of GRB 110428A with the EVLA
  13. GRB 110519A, Swift-BAT refined analysis
  14. GRB 110519A: Swift detection of a burst
  15. GRB 110503A optical observation
  16. GRB 110426A: Fermi GBM detection
  17. GRB 110428A: Fermi-GBM observation
  18. GRB 110503A: TAROT Calern observatory optical observations
  19. GRB 110503A: Jet Break seen from TLS
  20. GRB 110503A optical observations
  21. Konus-Wind observation of GRB 110503A
  22. GRB 110422A: MASTER first 30 min OT light curve
  23. GRB 110422A: Herschel FIR observation preliminary report
  24. GRB 110503A: optical observation in CrAO
  25. GRB 110503A: R-band Detection
  26. GRB 110503A: Centimeter observation from EVLA
  27. GRB 110503A: Millimeter observation from SMA
  28. GRB 110503A: SARA-N Observations and Photometric Calibration
  29. GRB 110503A: Swift/UVOT Observations
  30. GRB 110503A: Swift-XRT refined Analysis
  31. GRB 110503A: PAIRITEL NIR Detection
  32. GRB 110503A: redshift confirmation from TNG
  33. GRB 110503A - TLS Afterglow Observations
  34. GRB 110503A: Swift-BAT refined analysis
  35. GRB 110503A: NOT afterglow photometry
  36. GRB 110503A: Redshift from 10.4m GTC
  37. GRB 110503A: Enhanced Swift-XRT position
  38. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  39. GRB 110426A: Swift/XRT non-detection
  40. GRB 110428A : X-ray afterglow confirmation
  41. GRB 110428A: Suzaku WAM observation of the prompt emission
  42. GRB 110422A: optical observations in CrAO
  43. GRB 110428A : Swift-XRT observations
  44. Konus-Wind observation of GRB 110428A
  45. GRB 110428A: Fermi-LAT Detection
  46. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  47. GRB 110426A: MAXI/GSC detection of a GRB
  48. GRB 110422A: optical observations in CrAO, second epoch
  49. GRB 110422A: Redshift confirmation from GTC
  50. GRB 110422A: tentative redshift from TNG
  51. GRB 110422A: Suzaku WAM observation of the prompt emission
  52. GRB 110422A: Herschel observation scheduled
  53. GRB110422A: NOT optical follow-ups
  54. GRB 110422A: optical observations in CrAO
  55. Konus-Wind observation of GRB 110422A
  56. GRB 110422A: Further NOT observation
  57. GRB 110422A: Swift/UVOT Detection of optical afterglow
  58. GRB 110422A: Swift-XRT refined Analysis
  59. GRB 110422A: CQUEAN griz Observation
  60. GRB 110422A: THO optical observations
  61. GRB 110422A: Enhanced Swift-XRT position
  62. GRB 110422A: correction to the GCN circ. 11958
  63. GRB 110422A: TNG optical observations
  64. GRB 110422A: SAO RAS optical observations
  65. GRB 110422A: NOT optical observation
  66. GRB 110422A: MASTER earlier OT polarization observations
  67. GRB 110422A: Swift-BAT refined analysis
  68. GRB 110422A: Mondy optical observations
  69. GRB 110422A: Swift detection of a burst
  70. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  71. GRB 110420B: Fermi GBM observation
  72. Konus-Wind observation of GRB 110420A
  73. GRB 110420B: Spectral lag indicates short hard burst
  74. GRB 110420B, GROND observations
  75. GRB 110420A Swift/UVOT Observations
  76. GRB 110420B: Swift-XRT afterglow candidate
  77. GRB 110420B: Swift-BAT refined analysis
  78. GRB 110420A: Swift-BAT refined analysis
  79. GRB 110420B: Swift detection of a short hard burst
  80. GRB 110420A: Swift-XRT refined Analysis
  81. GRB 110420A: Enhanced Swift-XRT position
  82. GRB 110420A: Swift detection of a burst with optical counterpart
  83. GRB 110414A: GROND upper limits
  84. GRB 110414A: Swift-BAT Refined Analysis
  85. GRB 110414A: Swift-XRT refined Analysis
  86. GRB 110414A: Enhanced Swift-XRT position
  87. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  88. GRB 110414A : Faulkes Telescope North observations
  89. GRB 110414A: Swift detection of a burst
  90. GRB 110411A: PAIRITEL NIR Upper Limits
  91. GRB 110412A: Swift-BAT refined analysis
  92. GRB 110411A: optical limits from OSN
  93. GRB 110411A: Swift-XRT refined Analysis
  94. GRB 110412A: Fermi GBM observation
  95. GRB 110411A: MASTER prompt and follow-up optical limits
  96. GRB 110411A : Xinglong TNT OT candidate
  97. GRB 110412A: Swift detection of a burst
  98. GRB 110411A, Swift-BAT refined analysis
  99. GRB 110411A: Enhanced Swift-XRT position
  100. GRB 110411A: MASTER optical observations

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