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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"

34398 results found.

  1. GRB051227: further analysis of VLT images
  2. GRB 051227: optical afterglow
  3. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  4. GRB 051227: Gemini observations
  5. GRB 051227: Keck Spectroscopy
  6. GRB 051227: Magellan r'-band Imaging/Astrometry
  7. GRB 051227: refined analysis of VLT images
  8. GRB 051227: P60 Observations
  9. GRB 051227: MDM Observation
  10. GRB 051227: R-band object in the XRT error circle
  11. GRB 051227: Joint Swift-HETE Spectral Analysis
  12. GRB 051227: XRT refined analysis
  13. GRB 051227: Further analysis of the Swift-BAT burst
  14. GRB 051227: Refined analysis of the Swift-BAT burst
  15. GRB051227: SDSS pre-burst observations
  16. GRB 051227, optical observation
  17. GRB 051227: Swift detection of a burst
  18. IBAS_alert n. 2719 : not a real GRB
  19. Konus-Wind observation of GRB 051221A
  20. GRB051221A: Suzaku WAM observation of the prompt emission
  21. GRB 051221A: MDM Optical Observations
  22. GRB051016: analysis of the XMM-Newton observation
  23. GRB 051221A: Detection at 251nm with Swift UVOT
  24. GRB 051221A: Chandra Afterglow Position
  25. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  26. GRB 051221B: ROTSE-III Optical Limits
  27. GRB 051221B: TAROT optical limits
  28. GRB 051221A: WSRT Radio Observations
  29. GRB 051221: Redshift from Gemini
  30. GRB 051221: Continued fading of optical afterglow
  31. GRB 051221B: Refined analysis of the Swift-BAT burst
  32. Possible GRB 051221B: MDM Optical Detection
  33. GRB 051221A: RAPTOR Fading Counterpart Constraint
  34. GRB 051221B: BOOTES optical observations.
  35. Possible GRB 051221B: Swift XRT position
  36. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  37. Swift-BAT detection of a possible burst
  38. GRB 051221: Discovery of fading optical afterglow
  39. GRB 051221: Swift XRT refined analysis
  40. GRB 051221: Swift/UVOT upper limits
  41. GRB 051221: Possible nearby cluster
  42. GRB 051221: No variability in Gemini data
  43. GRB 051221: Correction to GCN #4368
  44. GRB 051221: Gemini observations
  45. GRB 051221: Improved astrometry of the IR counterpart
  46. GRB051221: K-band source
  47. GRB 051221: XRT position
  48. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  49. GRB 051221: IR Observations at GRB+1hr
  50. GRB 051221: Swift detection of a bright short burst
  51. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  52. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  53. GRB 051211B: optical afterglow
  54. Swift detection of an RS CVn flare star
  55. GRB051211A: possible optical candidate
  56. Swift Trigger 172767 is not a GRB
  57. GRB 051215: near-infrared observations
  58. GRB051215 - SDSS pre-burst observations
  59. GRB 051215: Swift detection of a possible burst
  60. GRB 051215: A short GRB in a cluster?
  61. GRB051105: optical observations
  62. GRB 051213: Swift-BAT refined analysis
  63. GRB 051211B, optical observation
  64. GRB 051213: Swift-BAT detection of a burst
  65. GRB 051211a: RTT150 optical observations
  66. GRB051211B, RBO optical observations
  67. GRB 051211A: Swift/UVOT upper limits
  68. GRB 051211B: Swift/UVOT upper limits - correction
  69. GRB 051211B: Swift/UVOT upper limits
  70. GRB 051211A,optical observation
  71. GRB 051211B: Swift XRT confirmation of the afterglow
  72. GRB051211B: Liverpool Telescope observation
  73. GRB 051211b: RTT150 optical observations
  74. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  75. GRB 051211B: Swift XRT Observations
  76. GRB 051210: Swift/UVOT upper limits
  77. GRB 051210: Magellan Imaging
  78. GRB 051211: TAROT optical limits
  79. GRB 051211B: a possible optical detection by TAROT
  80. GRB 051211B: a long GRB detected by INTEGRAL
  81. GRB 051211: Swift XRT upper limit
  82. GRB 051211:IAC80 optical observations
  83. HETE SXC localization of GRB 051211 (=H3979)
  84. GRB 051210: Optical imaging from Las Campanas
  85. GRB 051210: SALT detection limit
  86. GRB 051210: BAT further refined analysis of the short burst
  87. GRB 051210: Swift XRT refined analysis
  88. GRB 051210: FRAM early limit
  89. GRB 051210: Swift-BAT refined analysis of a short burst
  90. GRB 051210: A short GRB in a cluster?
  91. GRB 051210: Swift detection of a burst
  92. IPN observations of SGR1806-20
  93. An extraordinary long burst on December 3 from SGR1806-20
  94. IBAS Alert 2706 : not a real GRB
  95. GRB051117B: optical observation
  96. GRB051111: optical observaion
  97. Swift-BAT trigger 165579 is not a GRB
  98. GRB 051127: Swift-BAT detection of a possible burst
  99. GRB051117b: No Swift/UVOT Detection
  100. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction

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