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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"

26361 results found.

  1. MASTER:optical observations GRB030418
  2. MASTER:optical observations probable GRB030414
  3. GRB030418: Kiso near infrared observations
  4. GRB 030418: Optical afterglow
  5. OT GRB 030329: early UBVRcIc spectral evolution
  6. OT GRB 030329: early spectrum
  7. IPN triangulation of GRB030414 (small error box)
  8. IPN triangulation of GRB030413 (small error box)
  9. Superluminal motion in GRB 030329 (Correction)
  10. Superluminal motion in GRB 030329
  11. GRB030329, optical position
  12. IPN triangulation of GRB030406 (small error box)
  13. IPN triangulation of GRB050403 (small error box)
  14. GRB 030329: BVRI photometry at Asiago
  15. GRB 030329: VLT V-band photometry
  16. Kiso observation of the GRB030329 at April 6
  17. GRB 030329, color evolution
  18. GRB030328, UBVRcIc field photometry
  19. GRB 030329 Optical observations
  20. GRB030329: Kiso B and R band observations
  21. GRB030328: R upper limit after 6 hours by MASTER
  22. SDSS 0.5m PT observations of GRB030329 (correction)
  23. SDSS 0.5m PT observations of GRB030329
  24. GRB030329: final R-band light curve by MASTER
  25. GRB030329, optical observation
  26. GRB030329, new UBVRcIc field photometry
  27. GRB 030329, light curve and SN prediction
  28. GRB 030329, BRI photometry
  29. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  30. GRB030329: Optical observations at Teramo
  31. GRB 030329: Radio observations at GMRT
  32. Further AAVSO V,B,R observations of GRB030329
  33. GRB 030329: Additional Mt. Laguna Optical Observations
  34. GRB 030329: Observations with ANDICAM
  35. GRB030329: further optical photometry and evidence for a light curve discontinuity
  36. triangulation of GRB 030331 (single error box)
  37. GRB 030329: optical observations
  38. Photometry of GRB030329 - Constant OT Magnitude
  39. GRB030329 - OT brightens
  40. GRB 030329, optical photometry
  41. GRB 030324: Optical and NIR Observations
  42. GRB030329: R band light curve by MASTER
  43. GRB030329 - Light curve flattening
  44. GRB 030324, optical search
  45. GRB 030329, optical observations
  46. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  47. GRB030329a: detection by Konus-Wind
  48. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  49. GRB030329, BVRcIc field photometry
  50. GRB030329, SPM optical observations
  51. GRB 030329: Optical decay and synthesis
  52. GRB030329 optical observations
  53. GRB 030329: Optical pre-Imaging
  54. GRB 030329: Upper limit from 5.6 hours before trigger
  55. GRB030328: X-ray Afterglow Observed with Chandra
  56. GRB 030329, R-band observations
  57. GRB 030329: OT B and R photometry, decline rate
  58. GRB030329: Upper limits from recent and historical observations.
  59. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  60. GRB 030329: Optical Afterglow Observations
  61. GRB 030328: optical observations
  62. GRB 030329: Optical afterglow fading
  63. GRB 030328: OT photometry
  64. GRB030328: optical spectroscopy at TNG
  65. GRB030328: optical photometry at the TNG
  66. VLT spectra of GRB 030328
  67. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  68. GRB 030328: Optical observations
  69. GRB030324 optical observation
  70. GRB030131, BVRcIc field photometry
  71. Possible GRB030323 localized by INTEGRAL
  72. GRB030323: Detection on 2003/03/24
  73. IPN triangulation of GRB030326 (single small error box)
  74. IPN triangulation of GRB030325 (two small error boxes)
  75. GRB030323: V, R, I photometry
  76. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  77. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  78. VLT/FORS2 spectra of GRB 030323
  79. GRB030323, optical observations
  80. GRB030324, BVRcIc field photometry
  81. GRB030323, BVRcIc field calibration
  82. IPN triangulation of GRB030320 (small error box)
  83. Possible GRB 030320 localized by INTEGRAL
  84. IPN triangulation of GRB030306 (single small error box - REVISED)
  85. IPN triangulation of GRB030306 (single small error box)
  86. IPN triangulation of GRB030306 (two small error boxes)
  87. GRB030226, BVRc observations
  88. Chandra detection of the X-ray afterglow of GRB 030226
  89. GRB030227: Kiso optical upper limit
  90. GRB030227, BVRcIc field photometry
  91. GRB030226, BVRcIc field calibration
  92. GRB 030228, optical observations
  93. GRB 030227: Confirmed Optical Afterglow (S1-A)
  94. GRB 030227: fading of candidate optical afterglow 'S1-A'
  95. GRB030227:Optical observations
  96. GRB 030227, possible optical counterpart of XMM-Newton source
  97. GRB030227 - faint tentative OT candidate
  98. GRB 030226, optical observations
  99. XMM-Newton observation of GRB030227
  100. GRB030227: Kiso optical observations

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