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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"

26335 results found.

  1. GRB 051109: Rc and Ic observations
  2. GRB 051109: Swift-BAT refined analysis
  3. GRB 051109a: IR Photometry and Astrometry
  4. GRB051109: Swift detection of a burst
  5. GRB 051109a: IR Detections
  6. GRB051105B: Swift/XRT upper limit
  7. GRB051105B: Swift/UVOT upper limit
  8. GRB051103: MASTER: OT limit and host galaxy candidates
  9. GRB051028: Swift-XRT refined analysis
  10. GRB 051105a, observation from Naini Tal and OSN
  11. GRB 051105a: MDM Observations
  12. GRB 051105A: TNG optical observations
  13. GRB051105A: Swift/UVOT Observations
  14. GRB 051105A, radio observations
  15. GRB051103:_MASTER_optical_observations
  16. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  17. GRB 051105A, optical observations
  18. XRT observations of GRB 051105A
  19. GRB 051105b: ART optical limits
  20. GRB 051105B (INTEGRAL 2701): Optical observation
  21. GRB 051105: Swift detection of a short burst
  22. Recent GRB UBVRcIc field photometry
  23. GRB051028 SARA Observation
  24. GRB051028: optical observations
  25. GRB051028: Swift/UVOT upper limits
  26. GRB051028: Swift XRT Position
  27. GRB051028:MASTER observations
  28. GRB051021B: Swift/UVOT Upper limits
  29. GRB 051021, Optical Observations
  30. GRB 051022: XRT Refined Spectral and Temporal Analysis
  31. GRB051012: Swift-XRT analysis
  32. GRB051021B: Swift XRT refined analysis
  33. GRB 051022, mm counterpart
  34. GRB 051022: Swift/UVOT Upper Limits
  35. GRB051022: Radio Counterpart
  36. GRB051022: IR observations
  37. GRB051021A: Swift XRT refined analysis
  38. GRB051022: Optical Observations
  39. GRB051021b: Magellan IR Imaging
  40. GRB 051021, SMARTS optical/IR observations
  41. GRB051022: Swift XRT Position
  42. GRB 051021: P200 Ks Observations
  43. GRB 051022 (=H3950): SXC Flight Localization is Valid
  44. GRB051021: Swift/UVOT Upper Limits
  45. GRB 051021B: Refined analysis of the Swift-BAT burst
  46. GRB 051022: SSO40 Optical Observations
  47. GRB051022,optical observation
  48. GRB 051021,optical observation
  49. GRB 051021B: Swift detection of a burst
  50. GRB 051021 : optical afterglow observation at Lulin
  51. GRB 051021: Optical observations and candidate afterglow
  52. GRB051021.63
  53. GRB051021.6: MASTER optical observation
  54. GRB051021: A GRB Localized by HETE
  55. Swift-BAT triggered on a posible CR Shower or possible GRB
  56. GRB 051016b: Optical limit
  57. Afterglow candidate of GRB 051016B observed at Lulin
  58. GRB 051016A: Swift/UVOT upper limits
  59. GRB 051016B: refined analysis of the Swift/XRT data
  60. GRB 051016B: Swift/UVOT detection
  61. GRB 051016B,optical observation
  62. GRB 051016B : Optical follow-up at Lulin
  63. GRB 051016B: Refined analysis of the Swift-BAT burst
  64. GRB 051016B: Swift detection of a soft burst
  65. GRB 051016: Swift-BAT refined analysis
  66. GRB051016 XMM-Newton observation
  67. GRB051016: Swift XRT refined analysis.
  68. GRB 051016: PROMPT Observations
  69. GRB051016: Swift detection of a burst
  70. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  71. GRB 051012: Swift-BAT detection of burst yesterday
  72. Swift-BAT Trigger 159578 is a possible burst
  73. GRB 051006: Swift/UVOT Upper Limits
  74. GRB051008: optical candidate
  75. GRB 051008 - a low redshift low-luminosity burst?
  76. GRB051011: bright nebulae near error box
  77. GRB051011: MASTER optical observation
  78. GRB051008: Final refined analysis of the Swift-BAT burst
  79. GRB051008: Radio Observation
  80. GRB 051008, optical observations
  81. GRB 051008: early Swift XRT analysis
  82. GRB 051008: Swift UVOT Candidate
  83. GRB 051006: P60 Observations
  84. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  85. GRB 051006: optical observations at Sierra Nevada
  86. GRB051006: Refined analysis of the Swift-BAT burst
  87. GRB051006: Swift detection of a burst
  88. GRB 050906, summary of radio observations
  89. GRB051001: Swift UVOT Upper Limits
  90. GRB 050925: Second Epoch WSRT Radio Observations
  91. GRB 051001: I-band limit
  92. GRB 051001: AAT infra-red observations
  93. GRB 051001: Swift-BAT refined analysis
  94. GRB 051001: Swift Detection of a Burst
  95. GRB 050820A: NIR photometry at the TNG
  96. GRB050925: Swift/XRT limits
  97. GRB/SGR 050925: IR Observations
  98. GRB 050922C: break in the lightcurve
  99. GRB050925: Swift UVOT upper limits
  100. Refined analysis of the Swift-BAT soft short burst

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