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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"

26038 results found.

  1. GRB 061004: Nearby 2MASS Galaxy
  2. GRB 061004: Swift detection of a burst
  3. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  4. GRB 060928: Swift observations
  5. IPN triangulation of GRB060928 (long, exceptionally bright)
  6. GRB061002: Swift UVOT followup observations
  7. GRB 060930: near-IR afterglow candidate
  8. GRB 061002: Swift-XRT Team Refined Analysis
  9. VLA observations of GRB 060926
  10. GRB 061002, Swift-BAT refined analysis
  11. GRB061002: MASTER-VWF-Kislovodsk observations
  12. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  13. GRB 061002: Swift detection of a burst
  14. GRB 060908: Detection of a possible host
  15. GRB 060923A: Probable host galaxy in the R-band
  16. GRB 060807: Detection of a possible host galaxy
  17. GRB 060923A: VLA K-band Observations
  18. GRB 060929: Further XRT Refined Analysis
  19. GRB 060929: Swift/UVOT Optical Observations
  20. GRB 060927 : GAO 150cm telescope optical observation
  21. GRB060929: Swift-XRT refined analysis.
  22. GRB 060929, Swift-BAT further refined analysis - late-time flare
  23. GRB 060929: TNG K-band observations
  24. GRB 060929, Swift-BAT refined analysis
  25. GRB060929: Optical limit
  26. GRB 060929: BART observation
  27. GRB 060929: MASTER-VWF-Kislovodsk observations
  28. GRB 060929: BOOTES-IR & OSN observations
  29. Liverpool Telescope observations of GRB 060929
  30. GRB 060929: Swift detection of a burst
  31. GRB060908: optical observations
  32. GRB 060729: An update on the late-time Swift observations
  33. GRB 060927: Spectroscopic redshift z=5.6
  34. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  35. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  36. GRB 060927: Swift/UVOT Optical Observations
  37. GRB 060927: Early color
  38. GRB 060927: Swift XRT Team refined analysis
  39. GRB 060927, Swift-BAT refined analysis
  40. GRB 060927: Xinglong TNT optical observations
  41. GRB 060927: Possible host galaxy (star?) in the SDSS
  42. GRB 060927 : Kiso optical observation
  43. GRB060927: Faulkes Telescope South observation
  44. GRB060927 - SDSS Pre-Burst Observations
  45. GRB 060927: optical afterglow confirmation
  46. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  47. Swift XRT boresight
  48. GRB 060927: Swift detection of a burst
  49. GRB060926: VLT redshift
  50. GRB 060926: Swift-UVOT Detections
  51. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  52. GRB 060926: Swift XRT refined analysis
  53. GRB 060926, Swift-BAT refined analysis
  54. GRB 060923A: Radio Observations
  55. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  56. GRB 060926: BOOTES-IR observations
  57. GRB060926 OPTIMA-Burst optical observation
  58. GRB 060926: Swift detection of a burst
  59. GRB 060923C, Swift-BAT refined analysis
  60. GRB 060923C: VLA Observation
  61. GRB 060923C: NIR afterglow confirmed
  62. GRB 060923C: Gemini Observations and Afterglow Candidate
  63. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  64. GRB 060923C: VLT J-band observations
  65. GRB060923B: Swift/UVOT upper limits
  66. GRB 060923B: Swift XRT Refined Analysis
  67. GRB 060923C: Swift XRT refined analysis
  68. GRB 060923C, Swift-BAT partial refined analysis
  69. GRB 060923A: Swift XRT refined analysis
  70. GRB 060923C: Keck Observations
  71. GRB 060923A: Keck and Gemini Observations
  72. GRB 060923B, Swift-BAT refined analysis
  73. GRB060923C : Faulkes Telescope South optical limits
  74. GRB060923C: Faulkes Telescope North optical observations
  75. GRB 060923C: optical observation
  76. GRB 060923C: Swift detection of a burst
  77. GRB 060923B: Swift detection of a burst
  78. GRB 060923, Swift-BAT refined analysis
  79. GRB 060923: Early Super-LOTIS Observations
  80. GRB 060923: UKIRT nIR observations - candidate afterglow
  81. GRB060923: Faulkes Telescope North optical observations
  82. GRB 060923: KAIT observations
  83. GRB 060923: Swift detection of a burst
  84. Swift detection of IGR J17497-2821 (trigger 230504)
  85. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  86. GRB060919: Swift/UVOT optical observations
  87. GRB 060919 : Faulkes South Telescope Observations
  88. GRB 060919, Swift-BAT refined analysis
  89. GRB060919: XRT refined analysis
  90. GRB 060919: TAROT optical observations
  91. GRB 060919: Swift detection of a burst
  92. GRB 060912A: VLA Observation
  93. GRB 060912A: Probable Host Galaxy
  94. GRB060825: MAGIC telescope GeV observation
  95. Konus-Wind observation of GRB 060912
  96. GRB 060912: Redshift of nearby 2MASS galaxy
  97. GRB060912: optical observations
  98. GRB060912: Swift/UVOT Observations
  99. GRB060912: OPTIMA-Burst optical observations
  100. GRB 060912: Swift XRT Team Refined Analysis

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