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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"

36023 results found.

  1. GRB 040106 : peak flux
  2. GRB 040106 : a long GRB detected with INTEGRAL
  3. IPN triangulation of an intermediate burst from SGR1806-20
  4. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  5. GRB031225a triangulation (annulus)
  6. IPN triangulation of GRB031219 (large error box)
  7. GRB031220: Palomar Observations
  8. GRB 031220 : Kyoto Optical Observation
  9. GRB 031220: Subaru observation
  10. GRB 031220: Optical observation at Tokyo Tech
  11. GRB031220 : Optical Observation of Lulin Observatory
  12. GRB 031203 I-band monitoring
  13. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  14. GRB 2974 follow-up observations
  15. GRB 031203: Discovery of a dust echo
  16. GRB031214 triangulation (annulus), [repost of GCN2487, subject corrected]
  17. GRB030921 triangulation (annulus)
  18. GRB 031203: SMARTS optical monitoring
  19. GRB 021203: A Normal GRB viewed far off axis?
  20. GRB 031203: Variable Radio Source
  21. GRB 031203: Magellan spectrum of possible GRB host
  22. GRB 031203: Optical/IR Astrometry
  23. IPN/HETE localization of GRB031203B (=H2949; large error box)
  24. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  25. GRB 031203: Deep NIR NTT & VLT observations
  26. GRB031203: K' Photometry of the likely GRB host
  27. GRB 031203: Radio detection
  28. GRB 031203: Further reports on December 4 observations
  29. GRB 031203: IR NTTobservations do not confirm REM detection
  30. GRB031203 : Optical Observation of Lulin Observatory
  31. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  32. GRB 031203: Apparent Spectral Break
  33. GRB 031203: IR REM Observations
  34. GRB031203: Optical Observations
  35. GRB 031203 XMM-Newton observation
  36. GRB 031203: Optical/IR SMARTS Observations
  37. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  38. GRB 031203: further analysis of INTEGRAL data
  39. GRB 031203: A long GRB detected with INTEGRAL
  40. IPN triangulation of GRB031201 (large error box)
  41. IPN triangulation of GRB031130 (large error box)
  42. GRB031111A, prompt optical observations
  43. GRB 030329: Planned XMM-Newton Observation
  44. IPN triangulation of GRB031120 (two large error boxes)
  45. GRB 031111B (= H2925) : Kyoto Optical Observation
  46. IPN/HETE localization of GRB031109 (=H2917; large error box)
  47. IPN detection of activity from SGR1806-20
  48. GRB 031111, Radio observations
  49. IPN triangulation of GRB031114 (large error box)
  50. IPN triangulation of GRB031107 (two large error boxes)
  51. GRB 031111: Optical observations
  52. GRB 031111, optical observations
  53. SN 2003jd (SN/GRB?) -- X-ray Observations
  54. HETE Prompt GRB Spectral Analyses
  55. IPN triangulation of GRB031111 (=H2924): small error box
  56. IPN triangulation of GRB031108 (large error box)
  57. GRB030929/SN2003jd association unlikely based on IPN localiztion
  58. IPN triangulation of GRB031027 (small error box)
  59. IPN triangulation of GRB031026B (large error box)
  60. SN 2003jd (SN/GRB?), Radio Observations
  61. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  62. GRB 031026: Further Ic Observations
  63. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  64. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  65. IPN triangulation of GRB031024 (single error box)
  66. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  67. GRB 031026: Ic Observations
  68. GRB031026 : KISO optical follow-up observation
  69. IPN triangulation of GRB031024 (annulus)
  70. IPN triangulation of GRB031020 (large error box)
  71. IPN triangulation of GRB031016 (two large error boxes)
  72. IBAS alert 1180 refers to a burst from SGR 1806-20
  73. HETE Prompt GRB Light Curves and Color-Color Diagrams
  74. IPN triangulation of GRB031014 (annulus)
  75. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  76. IPN triangulation of GRB031008 (annulus)
  77. IPN detection of continued activity from SGR1806-20
  78. IPN triangulation of GRB031007 (two large error boxes)
  79. XRF 030723: Subaru Optical Observations
  80. IPN triangulation of GRB031004B (annulus)
  81. IPN triangulation of GRB031004A (short/hard; annulus)
  82. IPN triangulation of GRB030929 (short/hard; annulus)
  83. XRF 030824: Early follow-up observation at Kiso observatory
  84. XRF 030824: observations at CFHT
  85. IPN triangulation of GRB030926 (short/hard; large error box)
  86. IPN triangulation of GRB030922B (large error box)
  87. IPN triangulation of GRB030922A (large error box)
  88. IPN triangulation of GRB030921 (large error box)
  89. IPN triangulation of GRB030919 (large error box)
  90. GRB030922 triangulation (annulus)
  91. GRB030913: Subaru Optical Observations
  92. GRB 030913: ROTSE-3c Optical Observations
  93. GRB030913: OT's limit by MASTER
  94. GRB030921 triangulation (annulus)
  95. GRB030913, candidate afterglow observations
  96. GRB 030913, optical candidate
  97. GRB 030913, BOOTES observations
  98. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  99. GRB030913 (=H2849): TAROT Observations
  100. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER

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