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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: VR Photometry at TNG
  2. GRB030324: Candidate Optical Afterglow (Erratum)
  3. GRB030324: Candidate Optical Afterglow
  4. IPN triangulation of GRB030414 (small error box)
  5. GRB 030413: Optical Observations
  6. GRB 030329 Rc observations
  7. IPN triangulation of GRB030413 (small error box)
  8. IPN triangulation of GRB030410 (annulus)
  9. Superluminal motion in GRB 030329 (Correction)
  10. Superluminal motion in GRB 030329
  11. GRB 030329 and SN 2003dh
  12. GRB030329, optical position
  13. GRB 030329 VLBA Observations
  14. CORRECTION TO IPN TRIANGULATION OF GRB050403
  15. IPN triangulation of GRB030406 (small error box)
  16. IPN triangulation of GRB050403 (small error box)
  17. IPN triangulation of GRB030403 (annulus)
  18. GRB 030329: BVRI photometry at Asiago
  19. GRB 030329, light curve flattens
  20. GRB 030329: VLT V-band photometry
  21. If the SN/GRB connection confirmed
  22. GRB 030329: Supernova Confirmed
  23. GRB030329: RTT150 optical observations
  24. GRB030329: Near Infrared Observations at Gunma
  25. GRB030329: HET spectroscopic monitoring
  26. Kiso observation of the GRB030329 at April 6
  27. GRB 030329, color evolution
  28. GRB030328, UBVRcIc field photometry
  29. GRB030329: Optical observcations
  30. GRB030329: BV photographic observations
  31. GRB 030329 Optical observations
  32. GRB 030329, color evolution
  33. GRB 030329: possible color change
  34. GRB030329: RTT150 optical observations
  35. GRB 030329: Supernova Spectrum Emerging
  36. GRB030329: Kiso B and R band observations
  37. GRB030329: RTT150 optical observation
  38. GRB030329: More AAVSO VR obs
  39. GRB030328: R upper limit after 6 hours by MASTER
  40. GRB 030329: BV photographic observations
  41. GRB 030329: SARA Optical Observations
  42. GRB 030329: SARA Optical Observations
  43. GRB030329, fading resumes
  44. GRB 030329, BVRI photometry
  45. GRB030329: Optical observations
  46. SDSS 0.5m PT observations of GRB030329 (correction)
  47. SDSS 0.5m PT observations of GRB030329
  48. GRB 030329, Optical observations
  49. GRB 030329, nearby galaxies
  50. GRB030329, cessation of fading
  51. GRB030329: final R-band light curve by MASTER
  52. GRB030329 - more 15 GHz radio data
  53. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  54. GRB 030329: Sub-millimeter detection
  55. GRB 030329: SARA Optical Observations
  56. GRB 030329: SARA Optical Observations
  57. OT GRB light curves and SN predictions
  58. GRB030329, optical observation
  59. GRB030329, optical observation
  60. GRB030329, new UBVRcIc field photometry
  61. GRB 030329, light curve and SN prediction
  62. GRB030329: optical observations at Tokyo Tech
  63. GRB 030329: optical observations
  64. GRB030329: multiple re-brightening phases
  65. GRB 030329, BRI photometry
  66. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  67. GRB 030329 , SPM optical observations
  68. GRB030329: Optical observations at Teramo
  69. GRB 030329: Radio observations at GMRT
  70. GRB030329: more 15GHz observations
  71. Further AAVSO V,B,R observations of GRB030329
  72. GRB 030329: Additional Mt. Laguna Optical Observations
  73. GRB 030329: SARA Optical Observations
  74. GRB 030329: Observations with ANDICAM
  75. GRB030329: Optical observations
  76. GRB030329: further optical photometry and evidence for a light curve discontinuity
  77. GRB 030329: Correction to GCN 2056
  78. GRB 030329: fitting parameters and re-brightening
  79. GRB 030329: KAIT optical photometry
  80. GRB030329 Further RBO Optical Observations
  81. triangulation of GRB 030331 (single error box)
  82. GRB030329 - OT rebrightens
  83. GRB 030329: SARA Optical Observations
  84. AAVSO V & R observations of GRB030329
  85. IPN triangulation of GRB030331 (annulus)
  86. GRB 030329: optical observations
  87. IPN triangulation of GRB030329b (large error box)
  88. GRB 030329: beginning of the new fading phase in optical band
  89. GRB 030329, optical spectroscopy
  90. GRB 030329: fading X-ray afterglow with RXTE
  91. GRB 030329: optical photometry
  92. GRB030329: Optical observations
  93. Photometry of GRB030329 - Constant OT Magnitude
  94. GRB 030329, R-band observations
  95. GRB 030329, R-band light curve
  96. GRB 030329: further optical observations
  97. GRB030329 - OT brightens
  98. GRB 030329: OT observations at Kanazawa
  99. GRB030329 15 GHz radio observation
  100. GRB 030329 RBO V Optical Observations

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