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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"

42786 results found.

  1. GRB061004: Swift/UVOT optical observations
  2. GRB 061004: Swift-XRT Team Refined Analysis
  3. GRB 061004: Nearby 2MASS Galaxy
  4. GRB 061004: Swift detection of a burst
  5. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  6. Konus-Wind observation of GRB 060928
  7. GRB 060928: Suzaku/WAM observation of the prompt emission
  8. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  9. GRB 060928: Swift observations
  10. GRB 060928: RHESSI Spectral Fit
  11. IPN triangulation of GRB060928 (long, exceptionally bright)
  12. GRB061002: Swift UVOT followup observations
  13. GRB 060930: near-IR afterglow candidate
  14. GRB 061002: Swift-XRT Team Refined Analysis
  15. VLA observations of GRB 060926
  16. GRB061002 - SDSS Pre-Burst Observations
  17. GRB 061002, Swift-BAT refined analysis
  18. GRB061002: MASTER-VWF-Kislovodsk observations
  19. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  20. GRB 061002: Swift detection of a burst
  21. GRB 060908: Detection of a possible host
  22. GRB 060923A: Probable host galaxy in the R-band
  23. GRB 060807: Detection of a possible host galaxy
  24. GRB 060923A: VLA K-band Observations
  25. GRB060930: Faulkes Telescope South observation
  26. GRB 060930: Xinglong TNT optical observations
  27. GRB 060929: Further XRT Refined Analysis
  28. GRB 060929: Swift/UVOT Optical Observations
  29. GRB 060930: ROTSE-III Optical Limits
  30. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  31. GRB 060927 : GAO 150cm telescope optical observation
  32. GRB060929: Swift-XRT refined analysis.
  33. GRB 060929, Swift-BAT further refined analysis - late-time flare
  34. GRB 060929, Swift-BAT refined analysis
  35. GRB060929: Optical limit
  36. GRB 060929: MASTER-VWF-Kislovodsk observations
  37. GRB 060929: BOOTES-IR & OSN observations
  38. GRB 060929: Swift detection of a burst
  39. GRB060908: optical observations
  40. GRB 060729: An update on the late-time Swift observations
  41. GRB 060927: Spectroscopic redshift z=5.6
  42. IBAS Alert n.3501: not a GRB
  43. IBAS Alert n.3500: not a GRB
  44. GRB060923C: optical limit
  45. GRB060927: optical observations
  46. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  47. GRB 060927: Early color
  48. GRB 060927: Swift XRT Team refined analysis
  49. GRB 060927 optical limit
  50. GRB 060927, Swift-BAT refined analysis
  51. GRB 060927: Xinglong TNT optical observations
  52. GRB060926: improved redshift
  53. GRB 060927: Possible host galaxy (star?) in the SDSS
  54. GRB 060927 : Kiso optical observation
  55. GRB060927: Faulkes Telescope South observation
  56. GRB 060926: MASTER: first minutes decay
  57. GRB060927 - SDSS Pre-Burst Observations
  58. GRB 060927: optical afterglow confirmation
  59. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  60. Swift XRT boresight
  61. GRB 060927: Swift detection of a burst
  62. GRB060926: VLT redshift
  63. GRB 060926: Swift-UVOT Detections
  64. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  65. GRB 060926: OPTIMA-Burst -- further observations
  66. GRB 060926: Swift XRT refined analysis
  67. GRB 060926, Swift-BAT refined analysis
  68. GRB 060923A: Radio Observations
  69. GRB 060912A: Redshift of probable host galaxy
  70. GRB 060926: Watcher observations
  71. GRB060926 OPTIMA-Burst optical observation
  72. GRB 060926: Swift detection of a burst
  73. GRB 060923C, Swift-BAT refined analysis
  74. GRB 060923C: VLA Observation
  75. GRB 060923C: NIR afterglow confirmed
  76. GRB060923C: AROMA optical obsevation
  77. GRB 060923C: Gemini Observations and Afterglow Candidate
  78. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  79. GRB 060923C: VLT J-band observations
  80. GRB060923B: Swift/UVOT upper limits
  81. GRB 060923B: Swift XRT Refined Analysis
  82. GRB 060923C: Swift XRT refined analysis
  83. GRB 060923A: Swift XRT refined analysis
  84. GRB 060923C: Keck Observations
  85. GRB 060923A: Keck and Gemini Observations
  86. GRB 060923C: Xinglong TNT optical observations
  87. GRB 060923B, Swift-BAT refined analysis
  88. GRB060923C: Faulkes Telescope North optical observations
  89. GRB 060923C: Swift detection of a burst
  90. GRB 060923B: Swift detection of a burst
  91. GRB 060923, Swift-BAT refined analysis
  92. GRB 060923: Early Super-LOTIS Observations
  93. GRB 060923: UKIRT nIR observations - candidate afterglow
  94. GRB060923: Faulkes Telescope North optical observations
  95. GRB060923 - SDSS Pre-Burst Observations
  96. GRB 060923: KAIT observations
  97. GRB 060923: Swift detection of a burst
  98. Swift detection of IGR J17497-2821 (trigger 230504)
  99. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  100. GRB060919: Swift/UVOT optical observations

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