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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"

35958 results found.

  1. GRB060111B: RTT150, possible host galaxy
  2. GRB 060111B: Refined analysis of the Swift-BAT burst
  3. GRB 060110: MARGE observations
  4. GRB 060111(a): P60 Observations
  5. GRB 060111B: Gualba observatory limit
  6. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  7. GRB 060111B: Swift detection of a burst
  8. GRB 060111: Swift-BAT Refined Analysis
  9. GRB060111.2:_MASTER optical limit
  10. GRB 060108: VLT K-band observations
  11. GRB 060111: TAROT optical observation
  12. GRB 060111: possible UVOT counterpart
  13. GRB 060111: ROTSE-III Optical Limits
  14. GRB 060111: Swift detection of a burst
  15. GRB 060110: Mitsume optical observations
  16. GRB 060110: Swift-BAT refined analysis
  17. GRB 060109: Swift-BAT refined analysis
  18. GRB 060108: z-band imaging from Gemini-North
  19. GRB 060110a: RAPTOR detection of early optical emission.
  20. GRB 060110: UKIRT K-band observations
  21. GRB 060110: ROTSE-III Confirmation of Optical Counterpart
  22. GRB 060110: IR Candidate Afterglow
  23. GRB 060110: Super-LOTIS observations
  24. GRB 060110: Optical observation
  25. GRB 060110: Correction
  26. Correction to GRB 060109 XRT analysis
  27. GRB 050110: IR Observations
  28. GRB 060110: Optical limit
  29. GRB 060110: Swift-BAT detection of a burst
  30. GRB 060109: Refined Swift-XRT analysis
  31. GRB 060109: Swift/UVOT upper limits
  32. GRB060109, optical observation
  33. GRB 060108: ISAS early observations and near IR upper limit
  34. GRB060108: P200 Ks Observations
  35. GRB 060108: early UKIRT K-band observations
  36. Swift UVOT correction to GCN 4455
  37. GRB 060109: Swift Detection of a long burst
  38. GRB 060108: a dark burst?
  39. GRB 060108: Refined XRT analysis
  40. GRB 060108: VLT J-band observations
  41. GRB 060108: Mitsume optical observations
  42. GRB 060108: Swift/UVOT upper limits
  43. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  44. GRB060108: SDSS pre-burst observations
  45. GRB060108: Faulkes Telescope observation
  46. GRB 060108: Refined analysis of the Swift-BAT burst
  47. GRB 060108: Swift XRT position
  48. GRB060108: Swift detection of its 100th GRB
  49. GRB 060105: pseudo-z from spectral parameters of the prompt emission
  50. GRB 060105: Radio observations
  51. GRB 060105: MDM Observation
  52. Konus-Wind observation of GRB 060105
  53. GRB 060105: ISAS observations and near IR upper limit
  54. GRB 060105: Swift/UVOT upper limits
  55. GRB 060105: Mitsume optical observations
  56. GRB 060105: BAT refined analysis
  57. GRB 060102 - no XRT afterglow
  58. GRB 060105: XRT refined analysis
  59. GRB060105: Suzaku-XIS and -HXD observation plan
  60. GRB060105, optical observation
  61. GRB060105 : Kiso optical observation
  62. GRB060105: Swift detection of a bright long burst
  63. Swift-BAT trigger 175653 is not an astrophysical source
  64. GRB 060102: MDM Observation
  65. Swift-BAT trigger 175653 is probably not a GRB
  66. GRB 060102: Swift-BAT refined analysis
  67. Time Correction to GRB 060102
  68. GRB 060102: Swift-BAT detection of a burst
  69. GRB051211B: optical observations
  70. GRB051227: SARA Observations
  71. GRB 051221B: Optical Observations with Kuiper 1.54m
  72. GRB 051227: Likely host galaxy underlying afterglow position
  73. GRB 051227: optical observation
  74. GRB 051221A: VLA Radio Observations
  75. GRB 051227: Confirmed fading from Gemini observations
  76. GRB051227: further analysis of VLT images
  77. GRB 051227: optical afterglow
  78. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  79. GRB 051227: Gemini observations
  80. GRB 051227: Keck Spectroscopy
  81. GRB 051227: Magellan r'-band Imaging/Astrometry
  82. GRB 051227: refined analysis of VLT images
  83. GRB 051227: P60 Observations
  84. GRB 051227: MDM Observation
  85. GRB 051227: R-band object in the XRT error circle
  86. GRB 051227: Joint Swift-HETE Spectral Analysis
  87. GRB 051227: XRT refined analysis
  88. GRB 051227: Further analysis of the Swift-BAT burst
  89. GRB 051227: Refined analysis of the Swift-BAT burst
  90. GRB051227: SDSS pre-burst observations
  91. GRB 051227, optical observation
  92. GRB 051227: Swift detection of a burst
  93. IBAS_alert n. 2719 : not a real GRB
  94. Konus-Wind observation of GRB 051221A
  95. GRB051221A: Suzaku WAM observation of the prompt emission
  96. GRB 051221A: MDM Optical Observations
  97. GRB051016: analysis of the XMM-Newton observation
  98. GRB 051221A: Detection at 251nm with Swift UVOT
  99. GRB 051221A: Chandra Afterglow Position
  100. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst

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