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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"

20968 results found.

  1. GRB 060908: REM optical prompt observation
  2. GRB060904b optical detections (delayed report due to internet outage)
  3. GRB 060906: Swift-UVOT observations
  4. GRB 060906: FRAM observations - flash determination (airplane)
  5. GRB 060906: KAIT observations
  6. GRB 060906: Confirmation of P60 Optical Afterglow
  7. GRB 060906: observations with FRAM
  8. GRB 060906 (?): P60 Optical Afterglow Candidate
  9. GRB 060904A Milagro GeV/TeV Observations
  10. GRB060904b, optical observations
  11. GRB 060904b: SMARTS optical/IR afterglow observations
  12. GRB 060904B: RTT150 optical observations
  13. GRB060904A: Swift/UVOT optical observations
  14. GRB060904b: Optical observations with Swift/UVOT
  15. GRB 060904A: Suzaku-XIS and -HXD observation plan
  16. GRB 060904A: P60 Observations
  17. GRB 060904B: Optical observations at Crni Vrh
  18. GRB060904B: Watcher observations
  19. GRB 060904B BOOTES-IR and 1.5m OSN observations
  20. GRB 060904B: TAROT optical counterpart observations
  21. GRB060904B - SDSS Pre-Burst Observations
  22. GRB 060904: TAROT optical observations
  23. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  24. GRB060904 - SDSS Pre-Burst Observations
  25. GRB060901: Optical observations
  26. 060901: Swift UVOT followup observations
  27. GRB 060901: SMARTS optical/IR observations update
  28. GRB 060901: Swift/XRT Refined Analysis
  29. GRB 060901: SMARTS optical/IR observations
  30. GRB 060901: Swift/XRT Position
  31. GRB 060901: Watcher observations
  32. GRB 060605, observations using an Integral Field Unit
  33. GRB 060825: VLA observations
  34. GRB060826 - SDSS Pre-Burst Observations
  35. GRB060825: Liverpool Telescope optical observations
  36. GRB 060825: TNG optical observations
  37. GRB 060825: TAROT optical observations
  38. GRB 060825: P60 Observations
  39. GRB060825: BOOTES-IR optical observations
  40. GRB060801: host galaxy redshift
  41. Radio observations of GRB 060719
  42. GRB 060729, SMARTS optical/IR observations
  43. GRB 060814: Confirmation of IR afterglow
  44. GRB 060814: P60 Observations
  45. GRB 060814: P200 NIR Observations
  46. GRB 060814: Possible IR counterpart
  47. GRB060805B: optical observations
  48. GRB 060814: VLT optical limits
  49. GRB 060814 - SDSS Pre-Burst Observations
  50. GRB 060814: TAROT optical observations
  51. GRB051109B: Late-time Radio Observations
  52. Second VLA limit on new radio point source in SGR 1806-20
  53. GRB060714: optical observations
  54. GRB 060729: An update on the Swift XRT and UVOT observations
  55. GRB060717: optical observations
  56. GRB060807: Optical limiting magnitudes
  57. GRB 060805B: XRT Team Analysis
  58. GRB 060807: K- and R-band observations
  59. GRB060806 = SGR1806-20
  60. GRB060807 - SDSS Pre-burst Observations
  61. GRB 060807: Kanazawa R-band observation
  62. GRB 060801: Second Epoch WSRT Radio Observations
  63. GRB060805 Liverpool Telescope observations
  64. GRB 060805: P60 Observations
  65. GRB 060805: KAIT observations
  66. GRB 060805 - SDSS Pre-Burst Observations
  67. GRB 060804: Swift UVOT observations
  68. GRB 060728: Upper limits of the X-ray emission
  69. GRB 060801: WSRT Radio Observations
  70. GRB060801: Radio Observations
  71. GRB 051109B: Bright spiral host galaxy at low redshift
  72. GRB 060801: optical observations at FORS2/VLT
  73. GRB 060801: optical observations at Hanle and Calar Alto
  74. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  75. GRB 060218 / SN 2006aj Nebular Spectrum
  76. GRB 060729 redshift
  77. GRB 060729: Swift/UVOT Observations
  78. GRB 060728, SMARTS optical/IR observations
  79. Swift/XRT preliminary analysis
  80. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  81. GRB 060714: Swift/UVOT Observations
  82. GRB060719: prompt NIR observations with REM
  83. GRB 060714: NOT observations
  84. GRB 060719: near-infrared afterglow
  85. GRB 060719: VLT/ISAAC observations
  86. GRB 060719: further analysis of VLT observations
  87. GRB 060719: prompt PROMPT observations
  88. GRB060719: REM NIR Observations
  89. GRB 060719: Continued LCO optical observations
  90. GRB 060719: VLT observations
  91. GRB 060719: LCO optical observations
  92. GRB060714: optical observations
  93. GRB 060717: NOT observations
  94. GRB060717 - SDSS Pre-burst Observations
  95. GRB 060714: REM infrared observations
  96. GRB060714: optical observations
  97. GRB 060714 : Liverpool Telescope Observations
  98. GRB 060708: VLT spectroscopy
  99. GRB060708: MARGE low resolution spectrum observations
  100. GRB060714: optical observations

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