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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"

32697 results found.

  1. GRB 030329: SARA Optical Observations
  2. GRB030329, fading resumes
  3. GRB 030329, BVRI photometry
  4. SDSS 0.5m PT observations of GRB030329 (correction)
  5. SDSS 0.5m PT observations of GRB030329
  6. GRB 030329, Optical observations
  7. GRB 030329, nearby galaxies
  8. GRB030329, cessation of fading
  9. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  10. GRB 030329: Sub-millimeter detection
  11. GRB 030329: SARA Optical Observations
  12. GRB 030329: SARA Optical Observations
  13. OT GRB light curves and SN predictions
  14. GRB030329, optical observation
  15. GRB030329, new UBVRcIc field photometry
  16. GRB 030329, light curve and SN prediction
  17. GRB030329: optical observations at Tokyo Tech
  18. GRB 030329: optical observations
  19. GRB030329: multiple re-brightening phases
  20. GRB 030329, BRI photometry
  21. GRB 030329 , SPM optical observations
  22. GRB 030329: Radio observations at GMRT
  23. Further AAVSO V,B,R observations of GRB030329
  24. GRB 030329: Additional Mt. Laguna Optical Observations
  25. GRB 030329: SARA Optical Observations
  26. GRB 030329: Observations with ANDICAM
  27. GRB030329: further optical photometry and evidence for a light curve discontinuity
  28. GRB 030329: Correction to GCN 2056
  29. GRB 030329: fitting parameters and re-brightening
  30. GRB 030329: KAIT optical photometry
  31. GRB030329 Further RBO Optical Observations
  32. triangulation of GRB 030331 (single error box)
  33. GRB030329 - OT rebrightens
  34. GRB 030329: SARA Optical Observations
  35. AAVSO V & R observations of GRB030329
  36. IPN triangulation of GRB030331 (annulus)
  37. GRB 030329: optical observations
  38. IPN triangulation of GRB030329b (large error box)
  39. GRB 030329: beginning of the new fading phase in optical band
  40. GRB 030329, optical spectroscopy
  41. GRB 030329: fading X-ray afterglow with RXTE
  42. GRB 030329: optical photometry
  43. Photometry of GRB030329 - Constant OT Magnitude
  44. GRB 030329, R-band observations
  45. GRB 030329, R-band light curve
  46. GRB 030329: further optical observations
  47. GRB030329 - OT brightens
  48. GRB 030329: OT observations at Kanazawa
  49. GRB030329 15 GHz radio observation
  50. GRB 030329 RBO V Optical Observations
  51. GRB 030329, optical photometry
  52. GRB030329: Near Infrared Observations
  53. 030331 NOT A GRB
  54. INTEGRAL GRB 030331
  55. GRB 030324: Optical and NIR Observations
  56. GRB 030328, optical photometry
  57. GRB030329: R band light curve by MASTER
  58. GRB030329 - Light curve flattening
  59. GRB 030329: SARA Optical Observations
  60. GRB 030324, optical search
  61. GRB030329 - near contemporaneous optical limits from CONCAM
  62. GRB 030329, optical observations
  63. GRB 030329: Light curve observed during the change of its slope.
  64. GRB030329, BVRcIc field photometry
  65. GRB030329, SPM optical observations
  66. GRB 030329: Optical Decay
  67. Redshift of GRB 030329
  68. GRB030329: ROTSE network observes steepening of decay curve
  69. GRB 030329, optical photometry
  70. GRB 030329: Optical decay and synthesis
  71. GRB 030329: Radio Observations
  72. GRB 030329, optical spectroscopy
  73. GRB 030329: still bright
  74. GRB 030329: Optical pre-Imaging
  75. GRB 030329: visual observations
  76. GRB 030329: Upper limit from 5.6 hours before trigger
  77. GRB030328: R optical observation
  78. GRB 030323: Gemini South VRI obsevations.
  79. GRB030329: Optical observations
  80. GRB 030329, R-band observations, supplement
  81. GRB030329:optical observations by MASTER
  82. GRB 030329: optical observations
  83. GRB 030329, R-band observations
  84. GRB 030329: OT B and R photometry, decline rate
  85. GRB030329: Upper limits from recent and historical observations.
  86. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  87. RXTE detection of GRB 030329 afterglow
  88. GRB 030329: Optical Afterglow Observations
  89. GRB 030329: precise position from Kyoto images
  90. GRB 030328 Optical Observations
  91. GRB 030328: Optical observations
  92. GRB 030328: optical observations
  93. GRB 030329: Optical afterglow fading
  94. GRB 030329 follow-up
  95. GRB 030329: Optical afterglow candidate
  96. GRB 030329: OT candidate
  97. GRB 030329: Optical afterglow candidate
  98. GRB 030328: OT photometry
  99. VLT spectra of GRB 030328
  100. GRB 030328, optical spectroscopy

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