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

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