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

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