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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"

34224 results found.

  1. GRB 031220: Optical observation at Tokyo Tech
  2. GRB031220 : Optical Observation of Lulin Observatory
  3. GRB 031203 I-band monitoring
  4. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  5. GRB 2974 follow-up observations
  6. GRB 031203: Discovery of a dust echo
  7. GRB031214 triangulation (annulus), [repost of GCN2487, subject corrected]
  8. GRB030921 triangulation (annulus)
  9. GRB 031203: SMARTS optical monitoring
  10. GRB 021203: A Normal GRB viewed far off axis?
  11. GRB 031203: Variable Radio Source
  12. GRB 031203: Magellan spectrum of possible GRB host
  13. GRB 031203: Optical/IR Astrometry
  14. IPN/HETE localization of GRB031203B (=H2949; large error box)
  15. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  16. GRB 031203: Deep NIR NTT & VLT observations
  17. GRB031203: K' Photometry of the likely GRB host
  18. GRB 031203: Radio detection
  19. GRB 031203: Further reports on December 4 observations
  20. GRB 031203: IR NTTobservations do not confirm REM detection
  21. GRB031203 : Optical Observation of Lulin Observatory
  22. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  23. GRB 031203: Apparent Spectral Break
  24. GRB 031203: IR REM Observations
  25. GRB031203: Optical Observations
  26. GRB 031203 XMM-Newton observation
  27. GRB 031203: Optical/IR SMARTS Observations
  28. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  29. GRB 031203: further analysis of INTEGRAL data
  30. GRB 031203: A long GRB detected with INTEGRAL
  31. IPN triangulation of GRB031201 (large error box)
  32. IPN triangulation of GRB031130 (large error box)
  33. GRB031111A, prompt optical observations
  34. GRB 030329: Planned XMM-Newton Observation
  35. IPN triangulation of GRB031120 (two large error boxes)
  36. GRB 031111B (= H2925) : Kyoto Optical Observation
  37. IPN/HETE localization of GRB031109 (=H2917; large error box)
  38. IPN detection of activity from SGR1806-20
  39. GRB 031111, Radio observations
  40. IPN triangulation of GRB031114 (large error box)
  41. IPN triangulation of GRB031107 (two large error boxes)
  42. GRB 031111: Optical observations
  43. GRB 031111, optical observations
  44. SN 2003jd (SN/GRB?) -- X-ray Observations
  45. HETE Prompt GRB Spectral Analyses
  46. IPN triangulation of GRB031111 (=H2924): small error box
  47. IPN triangulation of GRB031108 (large error box)
  48. GRB030929/SN2003jd association unlikely based on IPN localiztion
  49. IPN triangulation of GRB031027 (small error box)
  50. IPN triangulation of GRB031026B (large error box)
  51. SN 2003jd (SN/GRB?), Radio Observations
  52. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  53. GRB 031026: Further Ic Observations
  54. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  55. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  56. IPN triangulation of GRB031024 (single error box)
  57. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  58. GRB 031026: Ic Observations
  59. GRB031026 : KISO optical follow-up observation
  60. IPN triangulation of GRB031024 (annulus)
  61. IPN triangulation of GRB031020 (large error box)
  62. IPN triangulation of GRB031016 (two large error boxes)
  63. IBAS alert 1180 refers to a burst from SGR 1806-20
  64. HETE Prompt GRB Light Curves and Color-Color Diagrams
  65. IPN triangulation of GRB031014 (annulus)
  66. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  67. IPN triangulation of GRB031008 (annulus)
  68. IPN detection of continued activity from SGR1806-20
  69. IPN triangulation of GRB031007 (two large error boxes)
  70. XRF 030723: Subaru Optical Observations
  71. IPN triangulation of GRB031004B (annulus)
  72. IPN triangulation of GRB031004A (short/hard; annulus)
  73. IPN triangulation of GRB030929 (short/hard; annulus)
  74. XRF 030824: Early follow-up observation at Kiso observatory
  75. XRF 030824: observations at CFHT
  76. IPN triangulation of GRB030926 (short/hard; large error box)
  77. IPN triangulation of GRB030922B (large error box)
  78. XRF 030723: Detection of the likely host galaxy
  79. IPN triangulation of GRB030922A (large error box)
  80. IPN triangulation of GRB030921 (large error box)
  81. IPN triangulation of GRB030919 (large error box)
  82. GRB030922 triangulation (annulus)
  83. GRB030913: Subaru Optical Observations
  84. GRB 030913: ROTSE-3c Optical Observations
  85. GRB030913: OT's limit by MASTER
  86. GRB030921 triangulation (annulus)
  87. GRB030913, candidate afterglow observations
  88. GRB 030913, optical candidate
  89. GRB 030913, BOOTES observations
  90. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  91. GRB030913 (=H2849): TAROT Observations
  92. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  93. Magellan Observations of GRB030725 (=H2779)
  94. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  95. IPN triangulation of GRB030908 (annulus)
  96. GRB 030913: Optical limit at RIKEN
  97. XRF030824: Optical observations
  98. IPN triangulation of GRB030903 (large error box)
  99. IPN triangulation of GRB030831 (annulus)
  100. IPN triangulation of GRB030830 (large error box)

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