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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

36077 results found.

  1. GRB030929/SN2003jd association unlikely based on IPN localiztion
  2. IPN triangulation of GRB031027 (small error box)
  3. IPN triangulation of GRB031026B (large error box)
  4. SN 2003jd (SN/GRB?), Radio Observations
  5. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  6. GRB 031026: Further Ic Observations
  7. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  8. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  9. IPN triangulation of GRB031024 (single error box)
  10. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  11. GRB 031026: Ic Observations
  12. GRB031026 : KISO optical follow-up observation
  13. IPN triangulation of GRB031024 (annulus)
  14. IPN triangulation of GRB031020 (large error box)
  15. IPN triangulation of GRB031016 (two large error boxes)
  16. IBAS alert 1180 refers to a burst from SGR 1806-20
  17. HETE Prompt GRB Light Curves and Color-Color Diagrams
  18. IPN triangulation of GRB031014 (annulus)
  19. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  20. IPN triangulation of GRB031008 (annulus)
  21. IPN detection of continued activity from SGR1806-20
  22. IPN triangulation of GRB031007 (two large error boxes)
  23. XRF 030723: Subaru Optical Observations
  24. IPN triangulation of GRB031004B (annulus)
  25. IPN triangulation of GRB031004A (short/hard; annulus)
  26. IPN triangulation of GRB030929 (short/hard; annulus)
  27. XRF 030824: Early follow-up observation at Kiso observatory
  28. XRF 030824: observations at CFHT
  29. IPN triangulation of GRB030926 (short/hard; large error box)
  30. IPN triangulation of GRB030922B (large error box)
  31. XRF 030723: Detection of the likely host galaxy
  32. IPN triangulation of GRB030922A (large error box)
  33. IPN triangulation of GRB030921 (large error box)
  34. IPN triangulation of GRB030919 (large error box)
  35. GRB030922 triangulation (annulus)
  36. GRB030913: Subaru Optical Observations
  37. GRB 030913: ROTSE-3c Optical Observations
  38. GRB030913: OT's limit by MASTER
  39. GRB030921 triangulation (annulus)
  40. GRB030913, candidate afterglow observations
  41. GRB 030913, optical candidate
  42. GRB 030913, BOOTES observations
  43. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  44. GRB030913 (=H2849): TAROT Observations
  45. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  46. Magellan Observations of GRB030725 (=H2779)
  47. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  48. IPN triangulation of GRB030908 (annulus)
  49. GRB 030913: Optical limit at RIKEN
  50. XRF030824: Optical observations
  51. IPN triangulation of GRB030903 (large error box)
  52. IPN triangulation of GRB030831 (annulus)
  53. IPN triangulation of GRB030830 (large error box)
  54. GRB 030824: Candidate Follow-Up
  55. IPN triangulation of GRB030827 (large error box)
  56. GRB 030823 observation at Ouda
  57. XRF030824: Second-epoch Palomar observations
  58. IPN triangulation of GRB030822 (annulus)
  59. GRB030823: Palomar observations
  60. XRF030824: Palomar observations
  61. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  62. IPN triangulation of GRB030821 (=H2814; refined error box)
  63. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  64. Summary of recent IPN and HETE detections of SGR bursts
  65. IPN triangulation of GRB030814 (annulus)
  66. IPN detection of continued activity from SGR1806-20
  67. 030813 SGR event (Konus-Wind observation)
  68. GRB 030817 = H2808 TAROT optical observations
  69. SGR 1808-20 (=H2802): A Possible new SGR
  70. GRB 021206 Optical Observations
  71. IPN triangulation of GRB030808 (two large error boxes)
  72. IPN triangulation of GRB030806 (large burst; large error box)
  73. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  74. IPN/HETE summary of recent bursts from SGR1806-20
  75. XRF 030723: Detection of a rebrightening in the optical afterglow
  76. GRB030725: Optical observations
  77. XRF030723, BVRcIc field photometry update
  78. IPN triangulation of GRB030801 (large error box)
  79. GRB021206 optical counterpart upper limit
  80. IPN triangulation of GRB030731 (annulus)
  81. IBAS GRB Alerts 1011-1017 NOT CONFIRMED
  82. IPN triangulation of GRB030725 (=H2779; small error box)
  83. XRF030723 (=H2777): Second Epoch Magellan Observations
  84. GRB 030725: optical observations.
  85. GRB030725, optical transient observations
  86. IPN triangulation of GRB030726 (large error box)
  87. IPN triangulation of GRB030722 (large error box)
  88. IPN triangulation of GRB030721 (large error box)
  89. XRF030723 Radio Observations
  90. XRF030723(=H2777): Chandra Observations
  91. XRF 030723: VLT spectra
  92. Magellan Observations of XRF030723 (=H2777)
  93. GRB030723: Upper limits from historical observations
  94. GRB030725, possible optical transient
  95. XRF030723: Palomar observations and proposed counterpart
  96. GRB030725 (=H2779): A Bright GRB Localized by HETE
  97. XRF030723: optical observations
  98. XRF030723 (= H2777): Chandra Observations Scheduled
  99. XRF030723, BVRcIc field photometry
  100. XRF030723, optical observations

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