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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"

28037 results found.

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

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