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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"

45470 results found.

  1. GRB051109A: further steepening in the X-ray light curve
  2. GRB051109A: XRT refined analysis
  3. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  4. GRB051109B: XRT position
  5. GRB 051109B: Super-LOTIS Observations
  6. GRB 051109B Kiso optical follow-up observation
  7. GRB051105B: REM Optical observation
  8. GRB 051109B: Swift detection of a burst
  9. GRB 051109: HET Optical Spectrum and Absorption Redshift
  10. GRB 051109: PROMPT Detections
  11. GRB 051109: Rc and Ic observations
  12. GRB051109: Early Super-LOTIS Detection
  13. GRB 051109: Swift-BAT refined analysis
  14. GRB 051109a: IR Photometry and Astrometry
  15. GRB 051109a: MDM Observations
  16. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  17. GRB051109: Swift detection of a burst
  18. GRB 051109a: IR Detections
  19. GRB 051109: ROTSE-III Detection of Possible Counterpart
  20. GRB051105B: Swift/XRT upper limit
  21. GRB051105B: Swift/UVOT upper limit
  22. GRB051103: optical observations
  23. GRB 051103, optical observations
  24. GRB051103: MASTER: OT limit and host galaxy candidates
  25. GRB051028: Swift-XRT refined analysis
  26. GRB 051105a, observation from Naini Tal and OSN
  27. GRB 051105A, 2nd epoch optical observations
  28. GRB 051105a: MDM Observations
  29. GRB 051105A: TNG optical observations
  30. GRB051105A: Swift/UVOT Observations
  31. GRB 051105A, radio observations
  32. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  33. GRB 051105A, optical observations
  34. XRT observations of GRB 051105A
  35. GRB 051105: Swift-BAT improved refined analysis
  36. GRB 051105b: ART optical limits
  37. GRB051105B - A long GRB detected by INTEGRAL
  38. GRB 051105B (INTEGRAL 2701): Optical observation
  39. GRB 051105: Swift-BAT refined analysis
  40. GRB 051105: Optical limit
  41. GRB 051105: Swift detection of a short burst
  42. IBAS Alert 2700: Not a GRB
  43. GRB 051016B host spectroscopy and redshift
  44. GRB051016B: optical observation
  45. Recent GRB UBVRcIc field photometry
  46. Konus-Wind observation of GRB 051028
  47. GRB 051022: RTT150 optical observations
  48. GRB051028 SARA Observation
  49. GRB051028: optical observations
  50. GRB051028: Swift/UVOT upper limits
  51. GRB051028: confirmation of the afterglow
  52. GRB051028: WHT optical candidate
  53. GRB051028: Swift XRT Position
  54. GRB051028:MASTER observations
  55. GRB 051028 (=H3951): A GRB localized by HETE
  56. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  57. GRB051022: Swift XRT measurement of jet break
  58. SGR 1806-20: continued moderate activity seen with INTEGRAL
  59. GRB051021B: Swift/UVOT Upper limits
  60. GRB 051021, Optical Observations
  61. GRB 051022: XRT Refined Spectral and Temporal Analysis
  62. GRB 051022, refined optical astrometry
  63. Chandra Observations of GRB 051022
  64. GRB051012: Swift-XRT analysis
  65. GRB 051022 Chandra Observations scheduled
  66. GRB051021B: Swift XRT refined analysis
  67. GRB051021a: optical observations
  68. GRB 051022: WSRT Radio Detection
  69. GRB 051022, mm counterpart
  70. GRB051022: host galaxy redshift
  71. GRB 051022: Swift/UVOT Upper Limits
  72. GRB051022: Radio Counterpart
  73. GRB051022: IR observations
  74. GRB 051022: SOAR JKs Observations
  75. GRB051021A: Swift XRT refined analysis
  76. Konus-Wind observation of GRB 051022
  77. GRB051022: Optical Observations
  78. GRB 051022: Magellan NIR imaging
  79. GRB 051021: PROMPT RcIc Observations
  80. GRB051021b: Magellan IR Imaging
  81. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  82. GRB 051021: Correction
  83. GRB 051021, SMARTS optical/IR observations
  84. GRB051022: Swift XRT Position
  85. GRB 051021: P200 Ks Observations
  86. IPN triangulation of GRB051022 (=H3950)
  87. GRB 051021: MDM Upper Limit
  88. GRB 051022 (=H3950): SXC Flight Localization is Valid
  89. GRB051021: Swift/UVOT Upper Limits
  90. GRB 051021B: Refined analysis of the Swift-BAT burst
  91. GRB 051022: SSO40 Optical Observations
  92. GRB051022,optical observation
  93. GRB 051022A: ROTSE-III Optical Limits
  94. GRB051022 (=H3590), A GRB Detected By HETE
  95. GRB 051022: Optical observations
  96. GRB 051021,optical observation
  97. GRB051021B: Swift XRT Position
  98. GRB 051021: SOAR NIR Observations
  99. GRB 051021B: Swift detection of a burst
  100. GRB051021: Swift XRT analysis

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