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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"

20382 results found.

  1. EVLA afterglow limits on the high z GRB090429B
  2. Swift J1644+57/GRB 110328A, Additional HST Observations
  3. GRB 110521A: MASTER prompt optical limit
  4. GRB 110521A: Swift/UVOT Upper Limits
  5. GRB 110520A: NOT optical follow-ups
  6. GRB 110521A - NOT optical observation
  7. GRB 110521A: Enhanced Swift-XRT position
  8. GRB 110521A: MASTER synchronous and early optical observations limit
  9. Swift/UVOT observations of GRB110520A
  10. GRB 110521A: Swift detection of a burst
  11. GRB 110520A: Swift-BAT refined analysis
  12. GRB 110520A: IAC80 I-band observations
  13. GRB 110520A: Enhanced Swift-XRT position
  14. GRB 110520A: WHT IR observations
  15. GRB 110520A - NOT optical observation
  16. GRB 110520A: TAROT Calern observatory optical observations
  17. GRB 110520A: Swift detection of a burst
  18. IPN localization of bright GRB 110518A
  19. GRB 110519A, Swift-BAT refined analysis
  20. GRB 110503A optical observation
  21. GRB 110503A: TAROT Calern observatory optical observations
  22. Konus-Wind observation of GRB 110503A
  23. GRB 110503A: optical observation in CrAO
  24. GRB 110503A: Centimeter observation from EVLA
  25. GRB 110503A: Millimeter observation from SMA
  26. GRB 110503A: SARA-N Observations and Photometric Calibration
  27. GRB 110503A: Swift/UVOT Observations
  28. GRB 110503A: PAIRITEL NIR Detection
  29. GRB 110503A: Swift-BAT refined analysis
  30. GRB 110503A: Enhanced Swift-XRT position
  31. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  32. GRB 110426A: Swift/XRT non-detection
  33. GRB 110428A : X-ray afterglow confirmation
  34. GRB 110428A: Suzaku WAM observation of the prompt emission
  35. GRB 110422A: optical observations in CrAO
  36. GRB 110428A : Swift-XRT observations
  37. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  38. GRB 110422A: optical observations in CrAO, second epoch
  39. GRB110422A: NOT optical follow-ups
  40. GRB 110422A: optical observations in CrAO
  41. GRB110422A: MITSuME Ishigakijima Optical Observation
  42. GRB 110422A: Further NOT observation
  43. GRB 110422A: Swift/UVOT Detection of optical afterglow
  44. GRB 110422A: Enhanced Swift-XRT position
  45. GRB 110422A: TNG optical observations
  46. GRB 110422A: SAO RAS optical observations
  47. GRB 110422A: NOT optical observation
  48. GRB 110422A: Mondy optical observations
  49. GRB 110422A: Swift detection of a burst
  50. GRB 110420B: Swift/UVOT Upper Limits
  51. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  52. GRB 110420B: Swift-XRT afterglow candidate retraction
  53. GRB 110420B: Spectral lag indicates short hard burst
  54. GRB 110420B, GROND observations
  55. GRB 110420A Swift/UVOT Observations
  56. GRB 110420A: Enhanced Swift-XRT position
  57. GRB 110420A: Swift detection of a burst with optical counterpart
  58. GRB110414A: MITSuME Ishigakijima Optical upper limits
  59. GRB 110414A: GROND upper limits
  60. GRB110414A: MITSuME Okayama Optical upper limits
  61. GRB 110414A: Swift/UVOT Upper limits
  62. GRB 110414A: Enhanced Swift-XRT position
  63. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  64. GRB 110414A : Faulkes Telescope North observations
  65. GRB 110414A: Swift detection of a burst
  66. GRB 110411A: PAIRITEL NIR Upper Limits
  67. GRB 110411A: Swift/UVOT Upper Limits
  68. GRB 110411A: Enhanced Swift-XRT position
  69. GRB 110411A: Swift detection of a burst
  70. GRB 110328A / Swift J164449.3+573451: R-band Monitoring
  71. GRB 110328A / Swift J164449.3+573451: optical observations
  72. GRB 110328A/Swift J164449.3+573451 UVOT Upper Limits
  73. GRB110407A: UVOT Upper Limits
  74. GRB 110407A: GROND Detection of the Optical Afterglow
  75. GRB 110407A: MITSuME Okayama and Ishigakijima Optical upper limits
  76. GRB 110407A: NOT optical observations
  77. GRB 110407A: Enhanced Swift-XRT position
  78. IPN triangulation of the bright GRB110406A
  79. GRB 110407A: Swift detection of a burst
  80. Konus-Wind observation of GRB 110406A
  81. GRB 110328A/Swift J164449.3+573451: BAT recent rate increase and pre-outburst,light curve
  82. GRB 110402A: fading optical afterglow
  83. GRB 110328/Swift J164449.3+573451: Chandra observations
  84. GRB 110328A / Swift J164449.3+573451, HST Observations
  85. GRB 110402A: Konus-Wind spectral lags and detailed energetics
  86. GRB 110402A: optical observations in Mondy
  87. GRB 110402A: MITSuME Okayama and Ishigakijima Optical upper limits
  88. GRB 110328A/Swift J164449.3+573451: SARA-N detection
  89. GRB 110402A: Swift/UVOT detection of afterglow candidate
  90. GRB 110402A: Spectral lag indicates short hard burst
  91. GRB 110402A: Konkoly observations
  92. GRB 110328A: Konkoly observations.
  93. GRB 110402A: early optical limit by "Pi of the Sky"
  94. GRB 110402A: further NOT observations
  95. GRB110328A/Swift J164449.3+573451: Fermi LAT Observations
  96. GRB 110402A: PAIRITEL NIR Upper Limits
  97. GRB 110402A: Enhanced Swift-XRT position
  98. GRB 110402A: NOT afterglow confirmation
  99. GRB 110402A: Swift detection of a burst
  100. GRB 110328A / Swift J164449.3+573451: Radio-optical/NIR Astrometry

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