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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. IPN triangulation of GRB030410 (annulus)
  2. Superluminal motion in GRB 030329 (Correction)
  3. Superluminal motion in GRB 030329
  4. GRB 030329 and SN 2003dh
  5. GRB030329, optical position
  6. GRB 030329 VLBA Observations
  7. CORRECTION TO IPN TRIANGULATION OF GRB050403
  8. IPN triangulation of GRB030406 (small error box)
  9. IPN triangulation of GRB050403 (small error box)
  10. IPN triangulation of GRB030403 (annulus)
  11. GRB 030329: BVRI photometry at Asiago
  12. GRB 030329, light curve flattens
  13. GRB 030329: VLT V-band photometry
  14. If the SN/GRB connection confirmed
  15. GRB 030329: Supernova Confirmed
  16. GRB030329: RTT150 optical observations
  17. GRB030329: Near Infrared Observations at Gunma
  18. GRB030329: HET spectroscopic monitoring
  19. Kiso observation of the GRB030329 at April 6
  20. GRB 030329, color evolution
  21. GRB030328, UBVRcIc field photometry
  22. GRB030329: Optical observcations
  23. GRB030329: BV photographic observations
  24. GRB 030329 Optical observations
  25. GRB 030329, color evolution
  26. GRB 030329: possible color change
  27. GRB030329: RTT150 optical observations
  28. GRB 030329: Supernova Spectrum Emerging
  29. GRB030329: Kiso B and R band observations
  30. GRB030329: RTT150 optical observation
  31. GRB030329: More AAVSO VR obs
  32. GRB030328: R upper limit after 6 hours by MASTER
  33. GRB 030329: BV photographic observations
  34. GRB 030329: SARA Optical Observations
  35. GRB 030329: SARA Optical Observations
  36. GRB030329, fading resumes
  37. GRB 030329, BVRI photometry
  38. GRB030329: Optical observations
  39. SDSS 0.5m PT observations of GRB030329 (correction)
  40. SDSS 0.5m PT observations of GRB030329
  41. GRB 030329, Optical observations
  42. GRB 030329, nearby galaxies
  43. GRB030329, cessation of fading
  44. GRB030329: final R-band light curve by MASTER
  45. GRB030329 - more 15 GHz radio data
  46. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  47. GRB 030329: Sub-millimeter detection
  48. GRB 030329: SARA Optical Observations
  49. GRB 030329: SARA Optical Observations
  50. OT GRB light curves and SN predictions
  51. GRB030329, optical observation
  52. GRB030329, optical observation
  53. GRB030329, new UBVRcIc field photometry
  54. GRB 030329, light curve and SN prediction
  55. GRB030329: optical observations at Tokyo Tech
  56. GRB 030329: optical observations
  57. GRB030329: multiple re-brightening phases
  58. GRB 030329, BRI photometry
  59. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  60. GRB 030329 , SPM optical observations
  61. GRB030329: Optical observations at Teramo
  62. GRB 030329: Radio observations at GMRT
  63. GRB030329: more 15GHz observations
  64. Further AAVSO V,B,R observations of GRB030329
  65. GRB 030329: Additional Mt. Laguna Optical Observations
  66. GRB 030329: SARA Optical Observations
  67. GRB 030329: Observations with ANDICAM
  68. GRB030329: Optical observations
  69. GRB030329: further optical photometry and evidence for a light curve discontinuity
  70. GRB 030329: Correction to GCN 2056
  71. GRB 030329: fitting parameters and re-brightening
  72. GRB 030329: KAIT optical photometry
  73. GRB030329 Further RBO Optical Observations
  74. triangulation of GRB 030331 (single error box)
  75. GRB030329 - OT rebrightens
  76. GRB 030329: SARA Optical Observations
  77. AAVSO V & R observations of GRB030329
  78. IPN triangulation of GRB030331 (annulus)
  79. GRB 030329: optical observations
  80. IPN triangulation of GRB030329b (large error box)
  81. GRB 030329: beginning of the new fading phase in optical band
  82. GRB 030329, optical spectroscopy
  83. GRB 030329: fading X-ray afterglow with RXTE
  84. GRB 030329: optical photometry
  85. GRB030329: Optical observations
  86. Photometry of GRB030329 - Constant OT Magnitude
  87. GRB 030329, R-band observations
  88. GRB 030329, R-band light curve
  89. GRB 030329: further optical observations
  90. GRB030329 - OT brightens
  91. GRB 030329: OT observations at Kanazawa
  92. GRB030329 15 GHz radio observation
  93. GRB 030329 RBO V Optical Observations
  94. GRB 030329, optical photometry
  95. GRB030329: Near Infrared Observations
  96. 030331 NOT A GRB
  97. INTEGRAL GRB 030331
  98. GRB 030324: Optical and NIR Observations
  99. GRB 030328, optical photometry
  100. GRB030329: R band light curve by MASTER

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