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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"

16110 results found.

  1. GRB060923B: Swift/UVOT upper limits
  2. GRB 060923C: Keck Observations
  3. GRB 060923C: Xinglong TNT optical observations
  4. GRB060923C : Faulkes Telescope South optical limits
  5. GRB060923C: Faulkes Telescope North optical observations
  6. GRB 060923C: optical observation
  7. GRB060923: Faulkes Telescope North optical observations
  8. GRB060919: Swift/UVOT optical observations
  9. GRB 060919 : Faulkes South Telescope Observations
  10. GRB 060919: TAROT optical observations
  11. GRB 060912A: Probable Host Galaxy
  12. GRB 060912: Redshift of nearby 2MASS galaxy
  13. GRB060912: optical observations
  14. GRB060912: Swift/UVOT Observations
  15. GRB060912: OPTIMA-Burst optical observations
  16. GRB 060912: Correction to GCN 5559
  17. GRB 060912: Xinglong TNT optical observations
  18. GRB 060912: Swift detection of a burst with an optical afterglow
  19. GRB060906: Danish/DFOSC optical observations
  20. GRB 060908: Swift/UVOT Observations
  21. GRB 060908: Danish/DFOSC optical observations
  22. GRB 060904B: Kiso Optical observation
  23. GRB 060904A : Optical limit
  24. GRB 060908: REM optical prompt observation
  25. GRB 060908: Swift detection of a burst with a bright optical counterpart
  26. GRB060906 , optical observation
  27. GRB060904b optical detections (delayed report due to internet outage)
  28. GRB 060906: optical observation
  29. GRB 060906: Early RAPTOR optical limits
  30. GRB 060906: Swift/XRT Refined Analysis
  31. GRB 060906: Swift-UVOT observations
  32. VLT redshift of GRB 060906
  33. GRB 060906: KAIT observations
  34. GRB 060906: Confirmation of P60 Optical Afterglow
  35. GRB 060906 (?): P60 Optical Afterglow Candidate
  36. GRB060904b, optical observations
  37. GRB 060904b: SMARTS optical/IR afterglow observations
  38. GRB 060904B: RTT150 optical observations
  39. GRB060904A: Swift/UVOT optical observations
  40. GRB060904b: Optical observations with Swift/UVOT
  41. GRB 060904B: VLT redshift
  42. GRB 060904B: Optical observations at Crni Vrh
  43. GRB060904B: Watcher observations
  44. GRB 060904B BOOTES-IR and 1.5m OSN observations
  45. GRB 060904B: TAROT optical counterpart observations
  46. GRB 060904: TAROT optical observations
  47. GRB 060904B: Swift detection of a burst with optical counterpart
  48. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  49. GRB060901: Optical observations
  50. GRB 060901: SMARTS optical/IR observations update
  51. GRB 060901: SMARTS optical/IR observations
  52. GRB 060605, observations using an Integral Field Unit
  53. GRB 060826(?): Swift detection of a possible burst
  54. GRB060825: Liverpool Telescope optical observations
  55. GRB 060825: TNG optical observations
  56. GRB 060825: TAROT optical observations
  57. GRB060825: BOOTES-IR optical observations
  58. GRB 060729, SMARTS optical/IR observations
  59. GRB060814: Break in the XRT light curve
  60. GRB060813: Break in the XRT light curve
  61. GRB060805B: optical observations
  62. GRB060814: Swift/UVOT upper limits
  63. GRB 060814: VLT optical limits
  64. GRB 060814: TAROT optical observations
  65. GRB060813: Swift/UVOT upper limits
  66. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  67. GRB060807: Possible Highly Significant X-ray Emission Lines
  68. GRB060714: optical observations
  69. GRB 060729: An update on the Swift XRT and UVOT observations
  70. GRB060717: optical observations
  71. GRB060807: Optical limiting magnitudes
  72. GRB 060805B: optical observation at Sierra Nevada
  73. GRB 060805B: XRT Team Analysis
  74. GRB 060807: UVOT Upper limits
  75. GRB 060807: afterglow confirmation
  76. GRB 060807: K- and R-band observations
  77. GRB060807: optical afterglow candidate
  78. GRB060807: optical upper limit in white light
  79. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  80. GRB 060805B: Swift/UVOT Upper Limits
  81. GRB 060807, optical observation
  82. GRB 060807: optical limit
  83. GRB 060805: optical upper limit in R
  84. GRB 060805: Swift/UVOT Upper Limits
  85. GRB 060804: Swift UVOT observations
  86. GRB 060801: no variability of optical sources
  87. GRB 060801: WSRT Radio Observations
  88. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  89. GRB 051109B: Bright spiral host galaxy at low redshift
  90. GRB 060801: optical observations at FORS2/VLT
  91. GRB060801: Swift/UVOT Upper Limits
  92. GRB 060801: optical observations at Hanle and Calar Alto
  93. GRB060801: optical upper limit in R
  94. GRB 060801, optical observation
  95. GRB 060801: Kanazawa Optical Observation
  96. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  97. GRB 060719: TORTOREM optical upper limits
  98. GRB 060729: Swift/UVOT Detections
  99. GRB 060729: Swift/UVOT Observations
  100. GRB 060729: ROTSE-III Detection of Optical Counterpart

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