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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"

35935 results found.

  1. GRB 051221: IR Observations at GRB+1hr
  2. GRB 051221: Swift detection of a bright short burst
  3. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  4. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  5. GRB 051211B: optical afterglow
  6. Swift detection of an RS CVn flare star
  7. GRB051211A: possible optical candidate
  8. Swift Trigger 172767 is not a GRB
  9. GRB 051215: near-infrared observations
  10. GRB051215 - SDSS pre-burst observations
  11. GRB 051215: Swift detection of a possible burst
  12. GRB 051215: A short GRB in a cluster?
  13. GRB051105: optical observations
  14. GRB 051213: Swift-BAT refined analysis
  15. GRB 051211B, optical observation
  16. GRB 051213: Swift-BAT detection of a burst
  17. GRB 051211a: RTT150 optical observations
  18. GRB051211B, RBO optical observations
  19. GRB 051211A: Swift/UVOT upper limits
  20. GRB 051211B: Swift/UVOT upper limits - correction
  21. GRB 051211B: Swift/UVOT upper limits
  22. GRB 051211A,optical observation
  23. GRB 051211B: Swift XRT confirmation of the afterglow
  24. GRB051211B: Liverpool Telescope observation
  25. GRB 051211b: RTT150 optical observations
  26. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  27. GRB 051211B: Swift XRT Observations
  28. GRB 051210: Swift/UVOT upper limits
  29. GRB 051210: Magellan Imaging
  30. GRB 051211: TAROT optical limits
  31. GRB 051211B: a possible optical detection by TAROT
  32. GRB 051211B: a long GRB detected by INTEGRAL
  33. GRB 051211: Swift XRT upper limit
  34. GRB 051211:IAC80 optical observations
  35. HETE SXC localization of GRB 051211 (=H3979)
  36. GRB 051210: Optical imaging from Las Campanas
  37. GRB 051210: SALT detection limit
  38. GRB 051210: BAT further refined analysis of the short burst
  39. GRB 051210: Swift XRT refined analysis
  40. GRB 051210: FRAM early limit
  41. GRB 051210: Swift-BAT refined analysis of a short burst
  42. GRB 051210: A short GRB in a cluster?
  43. GRB 051210: Swift detection of a burst
  44. IPN observations of SGR1806-20
  45. An extraordinary long burst on December 3 from SGR1806-20
  46. IBAS Alert 2706 : not a real GRB
  47. GRB051117B: optical observation
  48. GRB051111: optical observaion
  49. Swift-BAT trigger 165579 is not a GRB
  50. GRB 051127: Swift-BAT detection of a possible burst
  51. GRB051117b: No Swift/UVOT Detection
  52. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  53. GRB 051117A: Swift/UVOT Detection of an Afterglow
  54. GRB051111: Suzaku WAM observation of the prompt emission
  55. GRB051008: Suzaku WAM observation of the prompt emission
  56. GRB 051109B: GAO 150cm telescope Optical limit
  57. GRB 051109A : GAO 150cm telescope Rc-band detection
  58. GRB 051021 Optical Observations
  59. GRB 051117B: MARGE Optical Limits
  60. GRB 051117A and B: Radio Observations
  61. GRB 051117B: R and I observations of possible host galaxy
  62. GRB 051117b: NIR observations
  63. GRB 051117A: Refined analysis of the Swift-BAT burst
  64. GRB 051117B: Refined analysis of the Swift-BAT burst
  65. GRB 051117B,optical observation
  66. GRB 051117B: Lulin R and I band observation
  67. GRB 051117B: Optical observations
  68. GRB 051117B: ROTSE-III Optical Limits
  69. GRB 051117B: Swift detection of a burst
  70. GRB 051117: Swift detection of a bright burst
  71. GRB 051028 Optical Observations
  72. GRB 051109B : Nainital upper limits
  73. GRB 051114: Radio Observations
  74. GRB 051114: Swift-BAT refined analysis
  75. GRB051109A optical observations
  76. GRB 051114: Swift-BAT detection of a short burst
  77. GRB 051111: Further spectroscopic analysis
  78. GRB 051111: Radio afterglow
  79. GRB 051113: Swift-BAT refined analysis
  80. GRB 051113: Swift-BAT detection of a burst
  81. GRB 051111: AEOS optical observations
  82. GRB051103: Radio Observations
  83. GRB 051109A Milagro GeV/TeV Observations
  84. GRB/SGR 050925: XMM-Newton ToO observation
  85. GRB051111: Swift/UVOT Observations
  86. GRB 051111A : R-band temporal decay index based on Lulin
  87. GRB 051111: Swift-BAT refined analysis
  88. GRB 051109A Optical Observations
  89. GRB 051111A : Lulin BVRI multi band afterglow observation
  90. GRB051111a: SARA Observations
  91. GRB 051111a: IR photometry
  92. GRB 051111: Keck HIRES redshift
  93. GRB 051111A: KAIT optical observations
  94. GRB 051111a: Afterglow fading in Ic
  95. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  96. GRB 051103 Milagro GeV/TeV Observations
  97. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  98. GRB 051008 Tautenburg Supernova Search
  99. GRB 051109B. Radio Observations
  100. GRB 051109A

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