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

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