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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: SARA Optical Observations
  2. GRB 030329: Observations with ANDICAM
  3. GRB030329: Optical observations
  4. GRB030329: further optical photometry and evidence for a light curve discontinuity
  5. GRB 030329: Correction to GCN 2056
  6. GRB 030329: fitting parameters and re-brightening
  7. GRB 030329: KAIT optical photometry
  8. GRB030329 Further RBO Optical Observations
  9. triangulation of GRB 030331 (single error box)
  10. GRB030329 - OT rebrightens
  11. GRB 030329: SARA Optical Observations
  12. AAVSO V & R observations of GRB030329
  13. IPN triangulation of GRB030331 (annulus)
  14. GRB 030329: optical observations
  15. IPN triangulation of GRB030329b (large error box)
  16. GRB 030329: beginning of the new fading phase in optical band
  17. GRB 030329, optical spectroscopy
  18. GRB 030329: fading X-ray afterglow with RXTE
  19. GRB 030329: optical photometry
  20. GRB030329: Optical observations
  21. Photometry of GRB030329 - Constant OT Magnitude
  22. GRB 030329, R-band observations
  23. GRB 030329, R-band light curve
  24. GRB 030329: further optical observations
  25. GRB030329 - OT brightens
  26. GRB 030329: OT observations at Kanazawa
  27. GRB030329 15 GHz radio observation
  28. GRB 030329 RBO V Optical Observations
  29. GRB 030329, optical photometry
  30. GRB030329: Near Infrared Observations
  31. 030331 NOT A GRB
  32. INTEGRAL GRB 030331
  33. GRB 030324: Optical and NIR Observations
  34. GRB 030328, optical photometry
  35. GRB030329: R band light curve by MASTER
  36. GRB030329 - Light curve flattening
  37. GRB 030329: SARA Optical Observations
  38. GRB 030324, optical search
  39. GRB030329 - near contemporaneous optical limits from CONCAM
  40. GRB030329: R and B observations
  41. GRB 030329, optical observations
  42. GRB030329: Optical observations
  43. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  44. GRB030329a: detection by Konus-Wind
  45. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  46. GRB 030329: Light curve observed during the change of its slope.
  47. GRB030329, BVRcIc field photometry
  48. GRB030329, SPM optical observations
  49. GRB 030329: Optical Decay
  50. Redshift of GRB 030329
  51. GRB030329: ROTSE network observes steepening of decay curve
  52. GRB 030329, optical photometry
  53. GRB 030329: Optical decay and synthesis
  54. GRB030329 optical observations
  55. GRB030329: optical spectroscopy with the TNG
  56. GRB 030329: Radio Observations
  57. GRB 030329, optical spectroscopy
  58. GRB 030329: still bright
  59. GRB 030329: Optical pre-Imaging
  60. GRB 030329: visual observations
  61. GRB 030329: Upper limit from 5.6 hours before trigger
  62. GRB030328: R optical observation
  63. GRB030328: X-ray Afterglow Observed with Chandra
  64. GRB 030323: Gemini South VRI obsevations.
  65. GRB030329: Optical observations
  66. GRB 030329, R-band observations, supplement
  67. GRB030329 optical observations
  68. GRB030329:optical observations by MASTER
  69. GRB 030329: optical observations
  70. GRB 030329, R-band observations
  71. GRB 030329: OT B and R photometry, decline rate
  72. GRB030329: Upper limits from recent and historical observations.
  73. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  74. RXTE detection of GRB 030329 afterglow
  75. GRB 030329: Optical Afterglow Observations
  76. GRB 030329: precise position from Kyoto images
  77. GRB 030328 Optical Observations
  78. GRB030328: Decay index
  79. GRB 030328: Optical observations
  80. GRB 030328: optical observations
  81. GRB 030329: Optical afterglow fading
  82. GRB 030329 follow-up
  83. GRB 030329: Optical afterglow candidate
  84. GRB 030329: OT candidate
  85. GRB 030329: Optical afterglow candidate
  86. GRB 030328: OT photometry
  87. GRB030328: optical spectroscopy at TNG
  88. GRB030328: optical photometry at the TNG
  89. VLT spectra of GRB 030328
  90. GRB 030328, optical spectroscopy
  91. GRB 030328, optical observations
  92. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  93. GRB 030328: Optical observations
  94. Re: GRB 030328: Finding chart
  95. GRB 030328: Finding chart
  96. GRB 030328: Optical afterglow candidate
  97. GRB030323 optical observations
  98. GRB030324 optical observation
  99. GRB030131, BVRcIc field photometry
  100. Possible GRB030323 localized by INTEGRAL

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