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

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