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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, BRI photometry
  2. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  3. GRB 030329 , SPM optical observations
  4. GRB030329: Optical observations at Teramo
  5. GRB 030329: Radio observations at GMRT
  6. GRB030329: more 15GHz observations
  7. Further AAVSO V,B,R observations of GRB030329
  8. GRB 030329: Additional Mt. Laguna Optical Observations
  9. GRB 030329: SARA Optical Observations
  10. GRB 030329: Observations with ANDICAM
  11. GRB030329: Optical observations
  12. GRB030329: further optical photometry and evidence for a light curve discontinuity
  13. GRB 030329: Correction to GCN 2056
  14. GRB 030329: fitting parameters and re-brightening
  15. GRB 030329: KAIT optical photometry
  16. GRB030329 Further RBO Optical Observations
  17. triangulation of GRB 030331 (single error box)
  18. GRB030329 - OT rebrightens
  19. GRB 030329: SARA Optical Observations
  20. AAVSO V & R observations of GRB030329
  21. IPN triangulation of GRB030331 (annulus)
  22. GRB 030329: optical observations
  23. IPN triangulation of GRB030329b (large error box)
  24. GRB 030329: beginning of the new fading phase in optical band
  25. GRB 030329, optical spectroscopy
  26. GRB 030329: fading X-ray afterglow with RXTE
  27. GRB 030329: optical photometry
  28. GRB030329: Optical observations
  29. Photometry of GRB030329 - Constant OT Magnitude
  30. GRB 030329, R-band observations
  31. GRB 030329, R-band light curve
  32. GRB 030329: further optical observations
  33. GRB030329 - OT brightens
  34. GRB 030329: OT observations at Kanazawa
  35. GRB030329 15 GHz radio observation
  36. GRB 030329 RBO V Optical Observations
  37. GRB 030329, optical photometry
  38. GRB030329: Near Infrared Observations
  39. 030331 NOT A GRB
  40. INTEGRAL GRB 030331
  41. GRB 030324: Optical and NIR Observations
  42. GRB 030328, optical photometry
  43. GRB030329: R band light curve by MASTER
  44. GRB030329 - Light curve flattening
  45. GRB 030329: SARA Optical Observations
  46. GRB 030324, optical search
  47. GRB030329 - near contemporaneous optical limits from CONCAM
  48. GRB030329: R and B observations
  49. GRB 030329, optical observations
  50. GRB030329: Optical observations
  51. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  52. GRB030329a: detection by Konus-Wind
  53. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  54. GRB 030329: Light curve observed during the change of its slope.
  55. GRB030329, BVRcIc field photometry
  56. GRB030329, SPM optical observations
  57. GRB 030329: Optical Decay
  58. Redshift of GRB 030329
  59. GRB030329: ROTSE network observes steepening of decay curve
  60. GRB 030329, optical photometry
  61. GRB 030329: Optical decay and synthesis
  62. GRB030329 optical observations
  63. GRB030329: optical spectroscopy with the TNG
  64. GRB 030329: Radio Observations
  65. GRB 030329, optical spectroscopy
  66. GRB 030329: still bright
  67. GRB 030329: Optical pre-Imaging
  68. GRB 030329: visual observations
  69. GRB 030329: Upper limit from 5.6 hours before trigger
  70. GRB030328: R optical observation
  71. GRB030328: X-ray Afterglow Observed with Chandra
  72. GRB 030323: Gemini South VRI obsevations.
  73. GRB030329: Optical observations
  74. GRB 030329, R-band observations, supplement
  75. GRB030329 optical observations
  76. GRB030329:optical observations by MASTER
  77. GRB 030329: optical observations
  78. GRB 030329, R-band observations
  79. GRB 030329: OT B and R photometry, decline rate
  80. GRB030329: Upper limits from recent and historical observations.
  81. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  82. RXTE detection of GRB 030329 afterglow
  83. GRB 030329: Optical Afterglow Observations
  84. GRB 030329: precise position from Kyoto images
  85. GRB 030328 Optical Observations
  86. GRB030328: Decay index
  87. GRB 030328: Optical observations
  88. GRB 030328: optical observations
  89. GRB 030329: Optical afterglow fading
  90. GRB 030329 follow-up
  91. GRB 030329: Optical afterglow candidate
  92. GRB 030329: OT candidate
  93. GRB 030329: Optical afterglow candidate
  94. GRB 030328: OT photometry
  95. GRB030328: optical spectroscopy at TNG
  96. GRB030328: optical photometry at the TNG
  97. VLT spectra of GRB 030328
  98. GRB 030328, optical spectroscopy
  99. GRB 030328, optical observations
  100. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC

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