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

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