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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"

32796 results found.

  1. GRB 031203: Apparent Spectral Break
  2. GRB 031203: IR REM Observations
  3. GRB031203: Optical Observations
  4. GRB 031203 XMM-Newton observation
  5. GRB 031203: Optical/IR SMARTS Observations
  6. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  7. GRB 031203: further analysis of INTEGRAL data
  8. GRB 031203: A long GRB detected with INTEGRAL
  9. IPN triangulation of GRB031201 (large error box)
  10. IPN triangulation of GRB031130 (large error box)
  11. GRB031111A, prompt optical observations
  12. GRB 030329: Planned XMM-Newton Observation
  13. IPN triangulation of GRB031120 (two large error boxes)
  14. GRB 031111B (= H2925) : Kyoto Optical Observation
  15. IPN/HETE localization of GRB031109 (=H2917; large error box)
  16. IPN detection of activity from SGR1806-20
  17. GRB 031111, Radio observations
  18. IPN triangulation of GRB031114 (large error box)
  19. IPN triangulation of GRB031107 (two large error boxes)
  20. GRB 031111: Optical observations
  21. GRB 031111, optical observations
  22. SN 2003jd (SN/GRB?) -- X-ray Observations
  23. HETE Prompt GRB Spectral Analyses
  24. IPN triangulation of GRB031111 (=H2924): small error box
  25. IPN triangulation of GRB031108 (large error box)
  26. GRB030929/SN2003jd association unlikely based on IPN localiztion
  27. IPN triangulation of GRB031027 (small error box)
  28. IPN triangulation of GRB031026B (large error box)
  29. SN 2003jd (SN/GRB?), Radio Observations
  30. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  31. GRB 031026: Further Ic Observations
  32. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  33. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  34. IPN triangulation of GRB031024 (single error box)
  35. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  36. GRB 031026: Ic Observations
  37. GRB031026 : KISO optical follow-up observation
  38. IPN triangulation of GRB031024 (annulus)
  39. IPN triangulation of GRB031020 (large error box)
  40. IPN triangulation of GRB031016 (two large error boxes)
  41. IBAS alert 1180 refers to a burst from SGR 1806-20
  42. HETE Prompt GRB Light Curves and Color-Color Diagrams
  43. IPN triangulation of GRB031014 (annulus)
  44. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  45. IPN triangulation of GRB031008 (annulus)
  46. IPN detection of continued activity from SGR1806-20
  47. IPN triangulation of GRB031007 (two large error boxes)
  48. XRF 030723: Subaru Optical Observations
  49. IPN triangulation of GRB031004B (annulus)
  50. IPN triangulation of GRB031004A (short/hard; annulus)
  51. IPN triangulation of GRB030929 (short/hard; annulus)
  52. XRF 030824: Early follow-up observation at Kiso observatory
  53. XRF 030824: observations at CFHT
  54. IPN triangulation of GRB030926 (short/hard; large error box)
  55. IPN triangulation of GRB030922B (large error box)
  56. IPN triangulation of GRB030922A (large error box)
  57. IPN triangulation of GRB030921 (large error box)
  58. IPN triangulation of GRB030919 (large error box)
  59. GRB030922 triangulation (annulus)
  60. GRB030913: Subaru Optical Observations
  61. GRB 030913: ROTSE-3c Optical Observations
  62. GRB030913: OT's limit by MASTER
  63. GRB030921 triangulation (annulus)
  64. GRB030913, candidate afterglow observations
  65. GRB 030913, optical candidate
  66. GRB 030913, BOOTES observations
  67. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  68. GRB030913 (=H2849): TAROT Observations
  69. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  70. Magellan Observations of GRB030725 (=H2779)
  71. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  72. IPN triangulation of GRB030908 (annulus)
  73. GRB 030913: Optical limit at RIKEN
  74. XRF030824: Optical observations
  75. IPN triangulation of GRB030903 (large error box)
  76. IPN triangulation of GRB030831 (annulus)
  77. IPN triangulation of GRB030830 (large error box)
  78. GRB 030824: Candidate Follow-Up
  79. IPN triangulation of GRB030827 (large error box)
  80. GRB 030823 observation at Ouda
  81. XRF030824: Second-epoch Palomar observations
  82. IPN triangulation of GRB030822 (annulus)
  83. GRB030823: Palomar observations
  84. XRF030824: Palomar observations
  85. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  86. IPN triangulation of GRB030821 (=H2814; refined error box)
  87. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  88. Summary of recent IPN and HETE detections of SGR bursts
  89. IPN triangulation of GRB030814 (annulus)
  90. IPN detection of continued activity from SGR1806-20
  91. 030813 SGR event (Konus-Wind observation)
  92. GRB 030817 = H2808 TAROT optical observations
  93. SGR 1808-20 (=H2802): A Possible new SGR
  94. GRB 021206 Optical Observations
  95. IPN triangulation of GRB030808 (two large error boxes)
  96. IPN triangulation of GRB030806 (large burst; large error box)
  97. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  98. IPN/HETE summary of recent bursts from SGR1806-20
  99. XRF 030723: Detection of a rebrightening in the optical afterglow
  100. GRB030725: Optical observations

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