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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"
  1. 030331 NOT A GRB
  2. INTEGRAL GRB 030331
  3. GRB 030324: Optical and NIR Observations
  4. GRB 030328, optical photometry
  5. GRB030329: R band light curve by MASTER
  6. GRB030329 - Light curve flattening
  7. GRB 030329: SARA Optical Observations
  8. GRB 030324, optical search
  9. GRB030329 - near contemporaneous optical limits from CONCAM
  10. GRB030329: R and B observations
  11. GRB 030329, optical observations
  12. GRB030329: Optical observations
  13. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  14. GRB030329a: detection by Konus-Wind
  15. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  16. GRB 030329: Light curve observed during the change of its slope.
  17. GRB030329, BVRcIc field photometry
  18. GRB030329, SPM optical observations
  19. GRB 030329: Optical Decay
  20. Redshift of GRB 030329
  21. GRB030329: ROTSE network observes steepening of decay curve
  22. GRB 030329, optical photometry
  23. GRB 030329: Optical decay and synthesis
  24. GRB030329 optical observations
  25. GRB030329: optical spectroscopy with the TNG
  26. GRB 030329: Radio Observations
  27. GRB 030329, optical spectroscopy
  28. GRB 030329: still bright
  29. GRB 030329: Optical pre-Imaging
  30. GRB 030329: visual observations
  31. GRB 030329: Upper limit from 5.6 hours before trigger
  32. GRB030328: R optical observation
  33. GRB030328: X-ray Afterglow Observed with Chandra
  34. GRB 030323: Gemini South VRI obsevations.
  35. GRB030329: Optical observations
  36. GRB 030329, R-band observations, supplement
  37. GRB030329 optical observations
  38. GRB030329:optical observations by MASTER
  39. GRB 030329: optical observations
  40. GRB 030329, R-band observations
  41. GRB 030329: OT B and R photometry, decline rate
  42. GRB030329: Upper limits from recent and historical observations.
  43. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  44. RXTE detection of GRB 030329 afterglow
  45. GRB 030329: Optical Afterglow Observations
  46. GRB 030329: precise position from Kyoto images
  47. GRB 030328 Optical Observations
  48. GRB030328: Decay index
  49. GRB 030328: Optical observations
  50. GRB 030328: optical observations
  51. GRB 030329: Optical afterglow fading
  52. GRB 030329 follow-up
  53. GRB 030329: Optical afterglow candidate
  54. GRB 030329: OT candidate
  55. GRB 030329: Optical afterglow candidate
  56. GRB 030328: OT photometry
  57. GRB030328: optical spectroscopy at TNG
  58. GRB030328: optical photometry at the TNG
  59. VLT spectra of GRB 030328
  60. GRB 030328, optical spectroscopy
  61. GRB 030328, optical observations
  62. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  63. GRB 030328: Optical observations
  64. Re: GRB 030328: Finding chart
  65. GRB 030328: Finding chart
  66. GRB 030328: Optical afterglow candidate
  67. GRB030323 optical observations
  68. GRB030324 optical observation
  69. GRB030131, BVRcIc field photometry
  70. Possible GRB030323 localized by INTEGRAL
  71. IPN triangulation of GRB030325 (final analysis)
  72. GRB030323: Detection on 2003/03/24
  73. IPN triangulation of GRB030326 (single small error box)
  74. GRB 030323: SARA Optical Observations
  75. IPN triangulation of GRB030325 (single small error box)
  76. GRB030324, optical observations
  77. GRB030324, optical observations
  78. IPN triangulation of GRB030325 (two small error boxes)
  79. GRB 030324: TAROT optical observations
  80. GRB030323: V, R, I photometry
  81. GRB 030324 (HETE #2641): Optical observations
  82. GRB030324, Optical Observations
  83. GRB030323: Upper limits from recent and historical observations.
  84. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  85. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  86. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  87. VLT/FORS2 spectra of GRB 030323
  88. GRB030323, ROTSE-III detection of possible optical counterpart
  89. GRB030323, optical observations
  90. GRB030324, BVRcIc field photometry
  91. GRB030323, possible optical counterpart
  92. GRB030323, BVRcIc field calibration
  93. GRB 030324 optical observations
  94. GRB 030320: Optical Observations
  95. GRB 030324, optical observations
  96. IPN triangulation of GRB030320B (annulus)
  97. IPN triangulation of GRB030320 (small error box)
  98. IPN triangulation of GRB030320
  99. Possible GRB 030320 localized by INTEGRAL
  100. GRB030226, addendum to GCN 1892

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