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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"

28047 results found.

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

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