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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"

28046 results found.

  1. Kiso observation of the GRB030329 at April 6
  2. GRB 030329, color evolution
  3. GRB030328, UBVRcIc field photometry
  4. GRB 030329 Optical observations
  5. GRB030329: Kiso B and R band observations
  6. GRB030328: R upper limit after 6 hours by MASTER
  7. SDSS 0.5m PT observations of GRB030329 (correction)
  8. SDSS 0.5m PT observations of GRB030329
  9. GRB030329: final R-band light curve by MASTER
  10. GRB030329, optical observation
  11. GRB030329, new UBVRcIc field photometry
  12. GRB 030329, light curve and SN prediction
  13. GRB 030329, BRI photometry
  14. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  15. GRB030329: Optical observations at Teramo
  16. GRB 030329: Radio observations at GMRT
  17. Further AAVSO V,B,R observations of GRB030329
  18. GRB 030329: Additional Mt. Laguna Optical Observations
  19. GRB 030329: Observations with ANDICAM
  20. GRB030329: further optical photometry and evidence for a light curve discontinuity
  21. triangulation of GRB 030331 (single error box)
  22. GRB 030329: optical observations
  23. Photometry of GRB030329 - Constant OT Magnitude
  24. GRB030329 - OT brightens
  25. GRB 030329, optical photometry
  26. GRB 030324: Optical and NIR Observations
  27. GRB030329: R band light curve by MASTER
  28. GRB030329 - Light curve flattening
  29. GRB 030324, optical search
  30. GRB 030329, optical observations
  31. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  32. GRB030329a: detection by Konus-Wind
  33. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  34. GRB030329, BVRcIc field photometry
  35. GRB030329, SPM optical observations
  36. GRB 030329: Optical decay and synthesis
  37. GRB030329 optical observations
  38. GRB 030329: Optical pre-Imaging
  39. GRB 030329: Upper limit from 5.6 hours before trigger
  40. GRB030328: X-ray Afterglow Observed with Chandra
  41. GRB 030329, R-band observations
  42. GRB 030329: OT B and R photometry, decline rate
  43. GRB030329: Upper limits from recent and historical observations.
  44. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  45. GRB 030329: Optical Afterglow Observations
  46. GRB 030328: optical observations
  47. GRB 030329: Optical afterglow fading
  48. GRB 030328: OT photometry
  49. GRB030328: optical spectroscopy at TNG
  50. GRB030328: optical photometry at the TNG
  51. VLT spectra of GRB 030328
  52. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  53. GRB 030328: Optical observations
  54. GRB030324 optical observation
  55. GRB030131, BVRcIc field photometry
  56. Possible GRB030323 localized by INTEGRAL
  57. GRB030323: Detection on 2003/03/24
  58. IPN triangulation of GRB030326 (single small error box)
  59. IPN triangulation of GRB030325 (two small error boxes)
  60. GRB030323: V, R, I photometry
  61. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  62. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  63. VLT/FORS2 spectra of GRB 030323
  64. GRB030323, optical observations
  65. GRB030324, BVRcIc field photometry
  66. GRB030323, BVRcIc field calibration
  67. IPN triangulation of GRB030320 (small error box)
  68. Possible GRB 030320 localized by INTEGRAL
  69. IPN triangulation of GRB030306 (single small error box - REVISED)
  70. IPN triangulation of GRB030306 (single small error box)
  71. IPN triangulation of GRB030306 (two small error boxes)
  72. GRB030226, BVRc observations
  73. Chandra detection of the X-ray afterglow of GRB 030226
  74. GRB030227: Kiso optical upper limit
  75. GRB030227, BVRcIc field photometry
  76. GRB030226, BVRcIc field calibration
  77. GRB 030228, optical observations
  78. GRB 030227: Confirmed Optical Afterglow (S1-A)
  79. GRB 030227: fading of candidate optical afterglow 'S1-A'
  80. GRB030227:Optical observations
  81. GRB 030227, possible optical counterpart of XMM-Newton source
  82. GRB030227 - faint tentative OT candidate
  83. GRB 030226, optical observations
  84. XMM-Newton observation of GRB030227
  85. GRB030227: Kiso optical observations
  86. GRB 030227: Kyoto optical observation
  87. GRB 030226, optical light curve
  88. GRB030227 localized by INTEGRAL
  89. GRB 030226 : Predicted light curve
  90. GRB030226: ESI spectroscopy
  91. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  92. GRB 030226 simultaneous optical observations
  93. GRB 030226, optical observations
  94. GRB030226: Optical decay index
  95. GRB 030226 Optical Spectra and R,I,z' Imaging
  96. GRB: Non-Referencing of GCN Circulars.
  97. IPN triangulation of GRB030217 (small error box)
  98. GRB 030131: marginal optical detection
  99. GRB 030204: Optical Observations
  100. GRB030204 field photometry

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