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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"

32595 results found.

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