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

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