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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: more 15GHz observations
  2. Further AAVSO V,B,R observations of GRB030329
  3. GRB 030329: Additional Mt. Laguna Optical Observations
  4. GRB 030329: SARA Optical Observations
  5. GRB 030329: Observations with ANDICAM
  6. GRB030329: Optical observations
  7. GRB030329: further optical photometry and evidence for a light curve discontinuity
  8. GRB 030329: Correction to GCN 2056
  9. GRB 030329: fitting parameters and re-brightening
  10. GRB 030329: KAIT optical photometry
  11. GRB030329 Further RBO Optical Observations
  12. triangulation of GRB 030331 (single error box)
  13. GRB030329 - OT rebrightens
  14. GRB 030329: SARA Optical Observations
  15. AAVSO V & R observations of GRB030329
  16. IPN triangulation of GRB030331 (annulus)
  17. GRB 030329: optical observations
  18. IPN triangulation of GRB030329b (large error box)
  19. GRB 030329: beginning of the new fading phase in optical band
  20. GRB 030329, optical spectroscopy
  21. GRB 030329: fading X-ray afterglow with RXTE
  22. GRB 030329: optical photometry
  23. GRB030329: Optical observations
  24. Photometry of GRB030329 - Constant OT Magnitude
  25. GRB 030329, R-band observations
  26. GRB 030329, R-band light curve
  27. GRB 030329: further optical observations
  28. GRB030329 - OT brightens
  29. GRB 030329: OT observations at Kanazawa
  30. GRB030329 15 GHz radio observation
  31. GRB 030329 RBO V Optical Observations
  32. GRB 030329, optical photometry
  33. GRB030329: Near Infrared Observations
  34. 030331 NOT A GRB
  35. INTEGRAL GRB 030331
  36. GRB 030324: Optical and NIR Observations
  37. GRB 030328, optical photometry
  38. GRB030329: R band light curve by MASTER
  39. GRB030329 - Light curve flattening
  40. GRB 030329: SARA Optical Observations
  41. GRB 030324, optical search
  42. GRB030329 - near contemporaneous optical limits from CONCAM
  43. GRB030329: R and B observations
  44. GRB 030329, optical observations
  45. GRB030329: Optical observations
  46. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  47. GRB030329a: detection by Konus-Wind
  48. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  49. GRB 030329: Light curve observed during the change of its slope.
  50. GRB030329, BVRcIc field photometry
  51. GRB030329, SPM optical observations
  52. GRB 030329: Optical Decay
  53. Redshift of GRB 030329
  54. GRB030329: ROTSE network observes steepening of decay curve
  55. GRB 030329, optical photometry
  56. GRB 030329: Optical decay and synthesis
  57. GRB030329 optical observations
  58. GRB030329: optical spectroscopy with the TNG
  59. GRB 030329: Radio Observations
  60. GRB 030329, optical spectroscopy
  61. GRB 030329: still bright
  62. GRB 030329: Optical pre-Imaging
  63. GRB 030329: visual observations
  64. GRB 030329: Upper limit from 5.6 hours before trigger
  65. GRB030328: R optical observation
  66. GRB030328: X-ray Afterglow Observed with Chandra
  67. GRB 030323: Gemini South VRI obsevations.
  68. GRB030329: Optical observations
  69. GRB 030329, R-band observations, supplement
  70. GRB030329 optical observations
  71. GRB030329:optical observations by MASTER
  72. GRB 030329: optical observations
  73. GRB 030329, R-band observations
  74. GRB 030329: OT B and R photometry, decline rate
  75. GRB030329: Upper limits from recent and historical observations.
  76. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  77. RXTE detection of GRB 030329 afterglow
  78. GRB 030329: Optical Afterglow Observations
  79. GRB 030329: precise position from Kyoto images
  80. GRB 030328 Optical Observations
  81. GRB030328: Decay index
  82. GRB 030328: Optical observations
  83. GRB 030328: optical observations
  84. GRB 030329: Optical afterglow fading
  85. GRB 030329 follow-up
  86. GRB 030329: Optical afterglow candidate
  87. GRB 030329: OT candidate
  88. GRB 030329: Optical afterglow candidate
  89. GRB 030328: OT photometry
  90. GRB030328: optical spectroscopy at TNG
  91. GRB030328: optical photometry at the TNG
  92. VLT spectra of GRB 030328
  93. GRB 030328, optical spectroscopy
  94. GRB 030328, optical observations
  95. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  96. GRB 030328: Optical observations
  97. Re: GRB 030328: Finding chart
  98. GRB 030328: Finding chart
  99. GRB 030328: Optical afterglow candidate
  100. GRB030323 optical observations

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