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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"

26733 results found.

  1. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  2. GRB030329: Optical observations at Teramo
  3. GRB 030329: Radio observations at GMRT
  4. Further AAVSO V,B,R observations of GRB030329
  5. GRB 030329: Additional Mt. Laguna Optical Observations
  6. GRB 030329: Observations with ANDICAM
  7. GRB030329: further optical photometry and evidence for a light curve discontinuity
  8. triangulation of GRB 030331 (single error box)
  9. GRB 030329: optical observations
  10. Photometry of GRB030329 - Constant OT Magnitude
  11. GRB030329 - OT brightens
  12. GRB 030329, optical photometry
  13. GRB 030324: Optical and NIR Observations
  14. GRB030329: R band light curve by MASTER
  15. GRB030329 - Light curve flattening
  16. GRB 030324, optical search
  17. GRB 030329, optical observations
  18. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  19. GRB030329a: detection by Konus-Wind
  20. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  21. GRB030329, BVRcIc field photometry
  22. GRB030329, SPM optical observations
  23. GRB 030329: Optical decay and synthesis
  24. GRB030329 optical observations
  25. GRB 030329: Optical pre-Imaging
  26. GRB 030329: Upper limit from 5.6 hours before trigger
  27. GRB030328: X-ray Afterglow Observed with Chandra
  28. GRB 030329, R-band observations
  29. GRB 030329: OT B and R photometry, decline rate
  30. GRB030329: Upper limits from recent and historical observations.
  31. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  32. GRB 030329: Optical Afterglow Observations
  33. GRB 030328: optical observations
  34. GRB 030329: Optical afterglow fading
  35. GRB 030328: OT photometry
  36. GRB030328: optical spectroscopy at TNG
  37. GRB030328: optical photometry at the TNG
  38. VLT spectra of GRB 030328
  39. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  40. GRB 030328: Optical observations
  41. GRB030324 optical observation
  42. GRB030131, BVRcIc field photometry
  43. Possible GRB030323 localized by INTEGRAL
  44. GRB030323: Detection on 2003/03/24
  45. IPN triangulation of GRB030326 (single small error box)
  46. IPN triangulation of GRB030325 (two small error boxes)
  47. GRB030323: V, R, I photometry
  48. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  49. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  50. VLT/FORS2 spectra of GRB 030323
  51. GRB030323, optical observations
  52. GRB030324, BVRcIc field photometry
  53. GRB030323, BVRcIc field calibration
  54. IPN triangulation of GRB030320 (small error box)
  55. Possible GRB 030320 localized by INTEGRAL
  56. IPN triangulation of GRB030306 (single small error box - REVISED)
  57. IPN triangulation of GRB030306 (single small error box)
  58. IPN triangulation of GRB030306 (two small error boxes)
  59. GRB030226, BVRc observations
  60. Chandra detection of the X-ray afterglow of GRB 030226
  61. GRB030227: Kiso optical upper limit
  62. GRB030227, BVRcIc field photometry
  63. GRB030226, BVRcIc field calibration
  64. GRB 030228, optical observations
  65. GRB 030227: Confirmed Optical Afterglow (S1-A)
  66. GRB 030227: fading of candidate optical afterglow 'S1-A'
  67. GRB030227:Optical observations
  68. GRB 030227, possible optical counterpart of XMM-Newton source
  69. GRB030227 - faint tentative OT candidate
  70. GRB 030226, optical observations
  71. XMM-Newton observation of GRB030227
  72. GRB030227: Kiso optical observations
  73. GRB 030227: Kyoto optical observation
  74. GRB 030226, optical light curve
  75. GRB030227 localized by INTEGRAL
  76. GRB 030226 : Predicted light curve
  77. GRB030226: ESI spectroscopy
  78. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  79. GRB 030226 simultaneous optical observations
  80. GRB 030226, optical observations
  81. GRB030226: Optical decay index
  82. GRB 030226 Optical Spectra and R,I,z' Imaging
  83. GRB: Non-Referencing of GCN Circulars.
  84. IPN triangulation of GRB030217 (small error box)
  85. GRB 030131: marginal optical detection
  86. GRB 030204: Optical Observations
  87. GRB030204 field photometry
  88. GRB020819: Kiso R and I band observations
  89. GRB030131: Candidate Optical Afterglow
  90. IPN triangulation of GRB030204 (small error box)
  91. GRB 030131, optical observations
  92. GRB 030131: afterglow candidate
  93. GRB 030115, late-time optical observations
  94. GRB030131: corrected INTEGRAL position
  95. GRB 020819: Host galaxy at Radio Position
  96. IPN triangulation of GRB030131
  97. GRB 030131 optical observations
  98. GRB 030131 optical observations
  99. A long GRB detected by INTEGRAL
  100. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m

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