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

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