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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"

45642 results found.

  1. GRB 060108: Swift/UVOT upper limits
  2. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  3. GRB060108: SDSS pre-burst observations
  4. GRB060108: Faulkes Telescope observation
  5. GRB060108, optical observation
  6. GRB 060108: Refined analysis of the Swift-BAT burst
  7. GRB 060108: Swift XRT position
  8. GRB060108: Swift detection of its 100th GRB
  9. GRB 060105: pseudo-z from spectral parameters of the prompt emission
  10. GRB 060105: Radio observations
  11. GRB 060105: MDM Observation
  12. Konus-Wind observation of GRB 060105
  13. GRB 060105: ISAS observations and near IR upper limit
  14. GRB 060105: Swift/UVOT upper limits
  15. GRB 060105: Mitsume optical observations
  16. GRB 060105: BAT refined analysis
  17. GRB 060102 - no XRT afterglow
  18. GRB 060105: XRT refined analysis
  19. GRB060105: Suzaku-XIS and -HXD observation plan
  20. GRB060105, optical observation
  21. GRB060105 : Kiso optical observation
  22. GRB060105: Swift detection of a bright long burst
  23. Swift-BAT trigger 175653 is not an astrophysical source
  24. GRB 060102: MDM Observation
  25. Swift-BAT trigger 175653 is probably not a GRB
  26. GRB 060102: Swift-BAT refined analysis
  27. Time Correction to GRB 060102
  28. GRB 060102: Swift-BAT detection of a burst
  29. GRB051211B: optical observations
  30. GRB051227: SARA Observations
  31. GRB 051221B: Optical Observations with Kuiper 1.54m
  32. GRB 051227: Likely host galaxy underlying afterglow position
  33. GRB 051227: optical observation
  34. GRB051221B: Radio observations
  35. GRB 051221A: VLA Radio Observations
  36. GRB051227: Radio Observations
  37. GRB 051227: Confirmed fading from Gemini observations
  38. GRB051227: further analysis of VLT images
  39. GRB 051227: optical afterglow
  40. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  41. GRB 051227: Gemini observations
  42. GRB 051227: Keck Spectroscopy
  43. GRB 051227: Magellan r'-band Imaging/Astrometry
  44. GRB 051227: refined analysis of VLT images
  45. GRB 051227: P60 Observations
  46. GRB 051227: MDM Observation
  47. GRB 051227: R-band object in the XRT error circle
  48. GRB 051227: Joint Swift-HETE Spectral Analysis
  49. GRB 051227: XRT refined analysis
  50. GRB 051227: Further analysis of the Swift-BAT burst
  51. GRB 051227: Refined analysis of the Swift-BAT burst
  52. GRB051227: SDSS pre-burst observations
  53. GRB 051227, optical observation
  54. GRB 051227: Swift detection of a burst
  55. GRB051117B: optical observation
  56. IBAS_alert n. 2719 : not a real GRB
  57. Konus-Wind observation of GRB 051221A
  58. GRB051221A: Suzaku WAM observation of the prompt emission
  59. GRB 051221A: MDM Optical Observations
  60. GRB051016: analysis of the XMM-Newton observation
  61. GRB 051221A: Detection at 251nm with Swift UVOT
  62. GRB 051221A: Chandra Afterglow Position
  63. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  64. GRB 051221B: ROTSE-III Optical Limits
  65. GRB 051221B: TAROT optical limits
  66. GRB 051221A: WSRT Radio Observations
  67. GRB 051221: Redshift from Gemini
  68. GRB 051221: Continued fading of optical afterglow
  69. GRB 051221B: Refined analysis of the Swift-BAT burst
  70. Possible GRB 051221B: MDM Optical Detection
  71. GRB 051221A: RAPTOR Fading Counterpart Constraint
  72. GRB 051221B: BOOTES optical observations.
  73. Possible GRB 051221B: Swift XRT position
  74. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  75. Swift-BAT detection of a possible burst
  76. GRB 051221: Discovery of fading optical afterglow
  77. GRB 051221: Swift XRT refined analysis
  78. GRB 051221: Swift/UVOT upper limits
  79. GRB 051221: Possible nearby cluster
  80. GRB 051221: No variability in Gemini data
  81. GRB 051221: Correction to GCN #4368
  82. GRB 051221: Gemini observations
  83. GRB 051221: Improved astrometry of the IR counterpart
  84. GRB051221: K-band source
  85. GRB 051221: XRT position
  86. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  87. GRB 051221: IR Observations at GRB+1hr
  88. GRB 051221: Swift detection of a bright short burst
  89. Refined analysis of the SWIFT J1626.6-5156
  90. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  91. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  92. GRB051211A (=H3979): Refined Analysis
  93. GRB 051211B: optical afterglow
  94. Swift detection of an RS CVn flare star
  95. GRB051211A: possible optical candidate
  96. Swift Trigger 172767 is not a GRB
  97. GRB 051215: near-infrared observations
  98. GRB051215 - SDSS pre-burst observations
  99. GRB 051215: Swift detection of a possible burst
  100. GRB 051215: A short GRB in a cluster?

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