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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').
  1. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  2. GRB030329a: detection by Konus-Wind
  3. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  4. GRB 030329: Light curve observed during the change of its slope.
  5. GRB030329, BVRcIc field photometry
  6. GRB030329, SPM optical observations
  7. GRB 030329: Optical Decay
  8. Redshift of GRB 030329
  9. GRB030329: ROTSE network observes steepening of decay curve
  10. GRB 030329, optical photometry
  11. GRB 030329: Optical decay and synthesis
  12. GRB030329 optical observations
  13. GRB030329: optical spectroscopy with the TNG
  14. GRB 030329: Radio Observations
  15. GRB 030329, optical spectroscopy
  16. GRB 030329: still bright
  17. GRB 030329: Optical pre-Imaging
  18. GRB 030329: visual observations
  19. GRB 030329: Upper limit from 5.6 hours before trigger
  20. GRB030328: R optical observation
  21. GRB030328: X-ray Afterglow Observed with Chandra
  22. GRB 030323: Gemini South VRI obsevations.
  23. GRB030329: Optical observations
  24. GRB 030329, R-band observations, supplement
  25. GRB030329 optical observations
  26. GRB030329:optical observations by MASTER
  27. GRB 030329: optical observations
  28. GRB 030329, R-band observations
  29. GRB 030329: OT B and R photometry, decline rate
  30. GRB030329: Upper limits from recent and historical observations.
  31. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  32. RXTE detection of GRB 030329 afterglow
  33. GRB 030329: Optical Afterglow Observations
  34. GRB 030329: precise position from Kyoto images
  35. GRB 030328 Optical Observations
  36. GRB030328: Decay index
  37. GRB 030328: Optical observations
  38. GRB 030328: optical observations
  39. GRB 030329: Optical afterglow fading
  40. GRB 030329 follow-up
  41. GRB 030329: Optical afterglow candidate
  42. GRB 030329: OT candidate
  43. GRB 030329: Optical afterglow candidate
  44. GRB 030328: OT photometry
  45. GRB030328: optical spectroscopy at TNG
  46. GRB030328: optical photometry at the TNG
  47. VLT spectra of GRB 030328
  48. GRB 030328, optical spectroscopy
  49. GRB 030328, optical observations
  50. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  51. GRB 030328: Optical observations
  52. Re: GRB 030328: Finding chart
  53. GRB 030328: Finding chart
  54. GRB 030328: Optical afterglow candidate
  55. GRB030323 optical observations
  56. GRB030324 optical observation
  57. GRB030131, BVRcIc field photometry
  58. Possible GRB030323 localized by INTEGRAL
  59. IPN triangulation of GRB030325 (final analysis)
  60. GRB030323: Detection on 2003/03/24
  61. IPN triangulation of GRB030326 (single small error box)
  62. GRB 030323: SARA Optical Observations
  63. IPN triangulation of GRB030325 (single small error box)
  64. GRB030324, optical observations
  65. GRB030324, optical observations
  66. IPN triangulation of GRB030325 (two small error boxes)
  67. GRB 030324: TAROT optical observations
  68. GRB030323: V, R, I photometry
  69. GRB 030324 (HETE #2641): Optical observations
  70. GRB030324, Optical Observations
  71. GRB030323: Upper limits from recent and historical observations.
  72. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  73. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  74. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  75. VLT/FORS2 spectra of GRB 030323
  76. GRB030323, ROTSE-III detection of possible optical counterpart
  77. GRB030323, optical observations
  78. GRB030324, BVRcIc field photometry
  79. GRB030323, possible optical counterpart
  80. GRB030323, BVRcIc field calibration
  81. GRB 030324 optical observations
  82. GRB 030320: Optical Observations
  83. GRB 030324, optical observations
  84. IPN triangulation of GRB030320B (annulus)
  85. IPN triangulation of GRB030320 (small error box)
  86. IPN triangulation of GRB030320
  87. Possible GRB 030320 localized by INTEGRAL
  88. GRB030226, addendum to GCN 1892
  89. IPN upper limit to a GRB associated with SN2003L
  90. IPN triangulation of GRB030317 (annulus)
  91. IPN triangulation of GRB030307 (annulus)
  92. GRB 030227: Optical limit at RIKEN
  93. GRB 030226 Optical observations
  94. IPN triangulation of GRB030306 (single small error box - REVISED)
  95. GRB030226: Optical observations at Asiago
  96. IPN triangulation of GRB030306 (single small error box)
  97. IPN triangulation of GRB030306 (two small error boxes)
  98. IPN triangulation of GRB030306 (intense; annulus only so far)
  99. GRB 030226: Optical observations
  100. GRB030226: Analysis of Chandra data

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