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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"

22914 results found.

  1. GRB 110503A: optical observation in CrAO
  2. GRB 110503A: Centimeter observation from EVLA
  3. GRB 110503A: Millimeter observation from SMA
  4. GRB 110503A: SARA-N Observations and Photometric Calibration
  5. GRB 110503A: Swift/UVOT Observations
  6. GRB 110503A: PAIRITEL NIR Detection
  7. GRB 110503A - TLS Afterglow Observations
  8. GRB 110503A: Enhanced Swift-XRT position
  9. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  10. GRB 110426A: Swift/XRT non-detection
  11. GRB 110428A : X-ray afterglow confirmation
  12. GRB 110422A: optical observations in CrAO
  13. GRB 110428A : Swift-XRT observations
  14. GRB 110428A: Fermi-LAT Detection
  15. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  16. GRB 110422A: optical observations in CrAO, second epoch
  17. GRB 110422A: Herschel observation scheduled
  18. GRB110422A: NOT optical follow-ups
  19. GRB 110422A: optical observations in CrAO
  20. GRB110422A: MITSuME Ishigakijima Optical Observation
  21. GRB 110422A: Further NOT observation
  22. GRB 110422A: Swift/UVOT Detection of optical afterglow
  23. GRB 110422A: THO optical observations
  24. GRB 110422A: Enhanced Swift-XRT position
  25. GRB 110422A: TNG optical observations
  26. GRB 110422A: SAO RAS optical observations
  27. GRB 110422A: NOT optical observation
  28. GRB 110422A: Swift-BAT refined analysis
  29. GRB 110422A: Mondy optical observations
  30. GRB 110422A: Swift detection of a burst
  31. GRB 110420B: Swift/UVOT Upper Limits
  32. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  33. GRB 110420B: Swift-XRT afterglow candidate retraction
  34. GRB 110420B, GROND observations
  35. GRB 110420A Swift/UVOT Observations
  36. GRB 110420B: Swift-XRT afterglow candidate
  37. GRB 110420B: Swift detection of a short hard burst
  38. GRB 110420A: Enhanced Swift-XRT position
  39. GRB 110420A: Swift detection of a burst with optical counterpart
  40. GRB110414A: MITSuME Ishigakijima Optical upper limits
  41. GRB 110414A: GROND upper limits
  42. GRB110414A: MITSuME Okayama Optical upper limits
  43. GRB 110414A: Swift/UVOT Upper limits
  44. GRB 110414A: Enhanced Swift-XRT position
  45. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  46. GRB 110414A: Swift detection of a burst
  47. GRB 110411A: PAIRITEL NIR Upper Limits
  48. GRB 110411A: Swift/UVOT Upper Limits
  49. GRB 110412A: Swift detection of a burst
  50. GRB 110411A: Enhanced Swift-XRT position
  51. GRB 110411A: Swift detection of a burst
  52. GRB 110328A / Swift J164449.3+573451: MASTER pre, prompt and follow-up observations
  53. GRB 110407A:VLF observations on 20.27kHz
  54. GRB 110328A / Swift J164449.3+573451: optical observations
  55. GRB 110328A/Swift J164449.3+573451 UVOT Upper Limits
  56. GRB 110406A: Positional coincidence with NGC 404
  57. GRB 110407A: MASTER optical observations
  58. GRB110407A: UVOT Upper Limits
  59. GRB 110407A: GROND Detection of the Optical Afterglow
  60. GRB 110407A: MITSuME Okayama and Ishigakijima Optical upper limits
  61. GRB 110407A: NOT optical observations
  62. GRB 110407A: Enhanced Swift-XRT position
  63. IPN triangulation of the bright GRB110406A
  64. GRB 110407A : Xinglong TNT upper limit
  65. GRB 110407A: Swift detection of a burst
  66. GRB 110328A/Swift J164449.3+573451: BAT recent rate increase and pre-outburst,light curve
  67. GRB 110406A: An exceptionally bright burst detected by INTEGRAL SPI-ACS
  68. GRB 110402A: fading optical afterglow
  69. GRB 110402A: LOAO Optical Observation
  70. GRB 110328A / Swift J164449.3+573451, HST Observations
  71. GRB 110328A / Swift J164449.3+573451: millimeter detection at PdBI
  72. GRB 110401A: Fermi GBM detection
  73. GRB 110402A: optical observations in Mondy
  74. GRB 110402A afterglow observation
  75. GRB 110402A: MITSuME Okayama and Ishigakijima Optical upper limits
  76. GRB 110328A/Swift J164449.3+573451: SARA-N detection
  77. GRB 110402A: Swift/UVOT detection of afterglow candidate
  78. GRB 110402A: Konkoly observations
  79. GRB 110328A: Konkoly observations.
  80. GRB 110402A: early optical limit by "Pi of the Sky"
  81. GRB 110402A: further NOT observations
  82. GRB110328A/Swift J164449.3+573451: Fermi LAT Observations
  83. GRB 110402A: PAIRITEL NIR Upper Limits
  84. GRB 110402A: Enhanced Swift-XRT position
  85. GRB 110402A: NOT afterglow confirmation
  86. GRB 110402A: Swift detection of a burst
  87. GRB 110328A / Swift J164449.3+573451: Radio-optical/NIR Astrometry
  88. GRB 110328A / Swift J164449.3+573451: Mondy optical observations
  89. GRB 110328/Swift J164449.3+573451: Fermi observations
  90. GRB 110328A / Swift J164449.3+573451: KASINICS K-band Observation
  91. GRB 110328A / Swift J164449.3+573451: X-ray analysis and a mini-blazar analogy
  92. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Detection in 2nd Epoch
  93. GRB 110328A / Swift J164449.3+573451: No optical variability of the optical counterpart
  94. GRB 110328A / Swift J164449.3+573451: Konkoly observations
  95. GRB 110328A / Swift J164449.3+573451: LOAO R-band Observation
  96. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Upper Limits
  97. GRB 110328A / Swift J164449.3+573451: optical observations
  98. GRB 110328A / Swift J164449.3+573451: optical spectroscopy from GTC
  99. GRB 110328B: Fermi GBM detection
  100. GRB 110328A / Swift J164449.3+573451: NOT optical observations.

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