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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"

28056 results found.

  1. OT GRB 030329: early spectrum
  2. IPN triangulation of GRB030414 (small error box)
  3. IPN triangulation of GRB030413 (small error box)
  4. Superluminal motion in GRB 030329 (Correction)
  5. Superluminal motion in GRB 030329
  6. GRB030329, optical position
  7. IPN triangulation of GRB030406 (small error box)
  8. IPN triangulation of GRB050403 (small error box)
  9. GRB 030329: BVRI photometry at Asiago
  10. GRB 030329: VLT V-band photometry
  11. Kiso observation of the GRB030329 at April 6
  12. GRB 030329, color evolution
  13. GRB030328, UBVRcIc field photometry
  14. GRB 030329 Optical observations
  15. GRB030329: Kiso B and R band observations
  16. GRB030328: R upper limit after 6 hours by MASTER
  17. SDSS 0.5m PT observations of GRB030329 (correction)
  18. SDSS 0.5m PT observations of GRB030329
  19. GRB030329: final R-band light curve by MASTER
  20. GRB030329, optical observation
  21. GRB030329, new UBVRcIc field photometry
  22. GRB 030329, light curve and SN prediction
  23. GRB 030329, BRI photometry
  24. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  25. GRB030329: Optical observations at Teramo
  26. GRB 030329: Radio observations at GMRT
  27. Further AAVSO V,B,R observations of GRB030329
  28. GRB 030329: Additional Mt. Laguna Optical Observations
  29. GRB 030329: Observations with ANDICAM
  30. GRB030329: further optical photometry and evidence for a light curve discontinuity
  31. triangulation of GRB 030331 (single error box)
  32. GRB 030329: optical observations
  33. Photometry of GRB030329 - Constant OT Magnitude
  34. GRB030329 - OT brightens
  35. GRB 030329, optical photometry
  36. GRB 030324: Optical and NIR Observations
  37. GRB030329: R band light curve by MASTER
  38. GRB030329 - Light curve flattening
  39. GRB 030324, optical search
  40. GRB 030329, optical observations
  41. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  42. GRB030329a: detection by Konus-Wind
  43. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  44. GRB030329, BVRcIc field photometry
  45. GRB030329, SPM optical observations
  46. GRB 030329: Optical decay and synthesis
  47. GRB030329 optical observations
  48. GRB 030329: Optical pre-Imaging
  49. GRB 030329: Upper limit from 5.6 hours before trigger
  50. GRB030328: X-ray Afterglow Observed with Chandra
  51. GRB 030329, R-band observations
  52. GRB 030329: OT B and R photometry, decline rate
  53. GRB030329: Upper limits from recent and historical observations.
  54. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  55. GRB 030329: Optical Afterglow Observations
  56. GRB 030328: optical observations
  57. GRB 030329: Optical afterglow fading
  58. GRB 030328: OT photometry
  59. GRB030328: optical spectroscopy at TNG
  60. GRB030328: optical photometry at the TNG
  61. VLT spectra of GRB 030328
  62. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  63. GRB 030328: Optical observations
  64. GRB030324 optical observation
  65. GRB030131, BVRcIc field photometry
  66. Possible GRB030323 localized by INTEGRAL
  67. GRB030323: Detection on 2003/03/24
  68. IPN triangulation of GRB030326 (single small error box)
  69. IPN triangulation of GRB030325 (two small error boxes)
  70. GRB030323: V, R, I photometry
  71. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  72. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  73. VLT/FORS2 spectra of GRB 030323
  74. GRB030323, optical observations
  75. GRB030324, BVRcIc field photometry
  76. GRB030323, BVRcIc field calibration
  77. IPN triangulation of GRB030320 (small error box)
  78. Possible GRB 030320 localized by INTEGRAL
  79. IPN triangulation of GRB030306 (single small error box - REVISED)
  80. IPN triangulation of GRB030306 (single small error box)
  81. IPN triangulation of GRB030306 (two small error boxes)
  82. GRB030226, BVRc observations
  83. Chandra detection of the X-ray afterglow of GRB 030226
  84. GRB030227: Kiso optical upper limit
  85. GRB030227, BVRcIc field photometry
  86. GRB030226, BVRcIc field calibration
  87. GRB 030228, optical observations
  88. GRB 030227: Confirmed Optical Afterglow (S1-A)
  89. GRB 030227: fading of candidate optical afterglow 'S1-A'
  90. GRB030227:Optical observations
  91. GRB 030227, possible optical counterpart of XMM-Newton source
  92. GRB030227 - faint tentative OT candidate
  93. GRB 030226, optical observations
  94. XMM-Newton observation of GRB030227
  95. GRB030227: Kiso optical observations
  96. GRB 030227: Kyoto optical observation
  97. GRB 030226, optical light curve
  98. GRB030227 localized by INTEGRAL
  99. GRB 030226 : Predicted light curve
  100. GRB030226: ESI spectroscopy

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