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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"

37503 results found.

  1. GRB 060105: BAT refined analysis
  2. GRB 060102 - no XRT afterglow
  3. GRB 060105: XRT refined analysis
  4. GRB060105: Suzaku-XIS and -HXD observation plan
  5. GRB060105, optical observation
  6. GRB060105 : Kiso optical observation
  7. GRB060105: Swift detection of a bright long burst
  8. Swift-BAT trigger 175653 is not an astrophysical source
  9. GRB 060102: MDM Observation
  10. Swift-BAT trigger 175653 is probably not a GRB
  11. GRB 060102: Swift-BAT refined analysis
  12. Time Correction to GRB 060102
  13. GRB 060102: Swift-BAT detection of a burst
  14. GRB051211B: optical observations
  15. GRB051227: SARA Observations
  16. GRB 051221B: Optical Observations with Kuiper 1.54m
  17. GRB 051227: Likely host galaxy underlying afterglow position
  18. GRB 051227: optical observation
  19. GRB 051221A: VLA Radio Observations
  20. GRB 051227: Confirmed fading from Gemini observations
  21. GRB051227: further analysis of VLT images
  22. GRB 051227: optical afterglow
  23. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  24. GRB 051227: Gemini observations
  25. GRB 051227: Keck Spectroscopy
  26. GRB 051227: Magellan r'-band Imaging/Astrometry
  27. GRB 051227: refined analysis of VLT images
  28. GRB 051227: P60 Observations
  29. GRB 051227: MDM Observation
  30. GRB 051227: R-band object in the XRT error circle
  31. GRB 051227: Joint Swift-HETE Spectral Analysis
  32. GRB 051227: XRT refined analysis
  33. GRB 051227: Further analysis of the Swift-BAT burst
  34. GRB 051227: Refined analysis of the Swift-BAT burst
  35. GRB051227: SDSS pre-burst observations
  36. GRB 051227, optical observation
  37. GRB 051227: Swift detection of a burst
  38. IBAS_alert n. 2719 : not a real GRB
  39. Konus-Wind observation of GRB 051221A
  40. GRB051221A: Suzaku WAM observation of the prompt emission
  41. GRB 051221A: MDM Optical Observations
  42. GRB051016: analysis of the XMM-Newton observation
  43. GRB 051221A: Detection at 251nm with Swift UVOT
  44. GRB 051221A: Chandra Afterglow Position
  45. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  46. GRB 051221B: ROTSE-III Optical Limits
  47. GRB 051221B: TAROT optical limits
  48. GRB 051221A: WSRT Radio Observations
  49. GRB 051221: Redshift from Gemini
  50. GRB 051221: Continued fading of optical afterglow
  51. GRB 051221B: Refined analysis of the Swift-BAT burst
  52. Possible GRB 051221B: MDM Optical Detection
  53. GRB 051221A: RAPTOR Fading Counterpart Constraint
  54. GRB 051221B: BOOTES optical observations.
  55. Possible GRB 051221B: Swift XRT position
  56. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  57. Swift-BAT detection of a possible burst
  58. GRB 051221: Discovery of fading optical afterglow
  59. GRB 051221: Swift XRT refined analysis
  60. GRB 051221: Swift/UVOT upper limits
  61. GRB 051221: Possible nearby cluster
  62. GRB 051221: No variability in Gemini data
  63. GRB 051221: Correction to GCN #4368
  64. GRB 051221: Gemini observations
  65. GRB 051221: Improved astrometry of the IR counterpart
  66. GRB051221: K-band source
  67. GRB 051221: XRT position
  68. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  69. GRB 051221: IR Observations at GRB+1hr
  70. GRB 051221: Swift detection of a bright short burst
  71. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  72. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  73. GRB 051211B: optical afterglow
  74. Swift detection of an RS CVn flare star
  75. GRB051211A: possible optical candidate
  76. Swift Trigger 172767 is not a GRB
  77. GRB 051215: near-infrared observations
  78. GRB051215 - SDSS pre-burst observations
  79. GRB 051215: Swift detection of a possible burst
  80. GRB 051215: A short GRB in a cluster?
  81. GRB051105: optical observations
  82. GRB 051213: Swift-BAT refined analysis
  83. GRB 051211B, optical observation
  84. GRB 051213: Swift-BAT detection of a burst
  85. GRB 051211a: RTT150 optical observations
  86. GRB051211B, RBO optical observations
  87. GRB 051211A: Swift/UVOT upper limits
  88. GRB 051211B: Swift/UVOT upper limits - correction
  89. GRB 051211B: Swift/UVOT upper limits
  90. GRB 051211A,optical observation
  91. GRB 051211B: Swift XRT confirmation of the afterglow
  92. GRB051211B: Liverpool Telescope observation
  93. GRB 051211b: RTT150 optical observations
  94. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  95. GRB 051211B: Swift XRT Observations
  96. GRB 051210: Swift/UVOT upper limits
  97. GRB 051210: Magellan Imaging
  98. GRB 051211: TAROT optical limits
  99. GRB 051211B: a possible optical detection by TAROT
  100. GRB 051211B: a long GRB detected by INTEGRAL

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