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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"

32510 results found.

  1. GRB 030329: fitting parameters and re-brightening
  2. GRB 030329: KAIT optical photometry
  3. GRB030329 Further RBO Optical Observations
  4. triangulation of GRB 030331 (single error box)
  5. GRB030329 - OT rebrightens
  6. GRB 030329: SARA Optical Observations
  7. AAVSO V & R observations of GRB030329
  8. GRB 030329: optical observations
  9. IPN triangulation of GRB030329b (large error box)
  10. GRB 030329: beginning of the new fading phase in optical band
  11. GRB 030329, optical spectroscopy
  12. GRB 030329: fading X-ray afterglow with RXTE
  13. GRB 030329: optical photometry
  14. GRB030329: Optical observations
  15. Photometry of GRB030329 - Constant OT Magnitude
  16. GRB 030329, R-band light curve
  17. GRB 030329: further optical observations
  18. GRB030329 - OT brightens
  19. GRB 030329: OT observations at Kanazawa
  20. GRB030329 15 GHz radio observation
  21. GRB 030329 RBO V Optical Observations
  22. GRB 030329, optical photometry
  23. GRB030329: Near Infrared Observations
  24. GRB 030324: Optical and NIR Observations
  25. GRB 030328, optical photometry
  26. GRB030329: R band light curve by MASTER
  27. GRB030329 - Light curve flattening
  28. GRB 030329: SARA Optical Observations
  29. GRB 030324, optical search
  30. GRB030329 - near contemporaneous optical limits from CONCAM
  31. GRB030329: R and B observations
  32. GRB 030329, optical observations
  33. GRB030329: Optical observations
  34. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  35. GRB030329a: detection by Konus-Wind
  36. GRB 030329: Light curve observed during the change of its slope.
  37. GRB030329, BVRcIc field photometry
  38. GRB030329, SPM optical observations
  39. GRB 030329: Optical Decay
  40. Redshift of GRB 030329
  41. GRB030329: ROTSE network observes steepening of decay curve
  42. GRB 030329, optical photometry
  43. GRB 030329: Optical decay and synthesis
  44. GRB030329 optical observations
  45. GRB030329: optical spectroscopy with the TNG
  46. GRB 030329: Radio Observations
  47. GRB 030329, optical spectroscopy
  48. GRB 030329: still bright
  49. GRB 030329: Optical pre-Imaging
  50. GRB 030329: visual observations
  51. GRB 030329: Upper limit from 5.6 hours before trigger
  52. GRB030328: R optical observation
  53. GRB030328: X-ray Afterglow Observed with Chandra
  54. GRB 030323: Gemini South VRI obsevations.
  55. GRB030329: Optical observations
  56. GRB030329:optical observations by MASTER
  57. GRB 030329: optical observations
  58. GRB 030329, R-band observations
  59. GRB 030329: OT B and R photometry, decline rate
  60. GRB030329: Upper limits from recent and historical observations.
  61. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  62. GRB 030329: Optical Afterglow Observations
  63. GRB 030329: precise position from Kyoto images
  64. GRB 030328 Optical Observations
  65. GRB030328: Decay index
  66. GRB 030328: Optical observations
  67. GRB 030328: optical observations
  68. GRB 030329: Optical afterglow fading
  69. GRB 030328: OT photometry
  70. GRB030328: optical spectroscopy at TNG
  71. GRB030328: optical photometry at the TNG
  72. VLT spectra of GRB 030328
  73. GRB 030328, optical spectroscopy
  74. GRB 030328, optical observations
  75. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  76. GRB 030328: Optical observations
  77. GRB 030328: Finding chart
  78. GRB030323 optical observations
  79. GRB030131, BVRcIc field photometry
  80. IPN triangulation of GRB030325 (final analysis)
  81. GRB030323: Detection on 2003/03/24
  82. GRB 030323: SARA Optical Observations
  83. IPN triangulation of GRB030325 (single small error box)
  84. GRB030324, optical observations
  85. GRB030324, optical observations
  86. GRB 030324: TAROT optical observations
  87. GRB030323: V, R, I photometry
  88. GRB 030324 (HETE #2641): Optical observations
  89. GRB030324, Optical Observations
  90. GRB030323: Upper limits from recent and historical observations.
  91. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  92. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  93. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  94. VLT/FORS2 spectra of GRB 030323
  95. GRB030323, ROTSE-III detection of possible optical counterpart
  96. GRB030323, optical observations
  97. GRB030323, possible optical counterpart
  98. GRB 030324 optical observations
  99. GRB 030320: Optical Observations
  100. IPN triangulation of GRB030320 (small error box)

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