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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"

41637 results found.

  1. GRB 030329: precise position from Kyoto images
  2. GRB 030328 Optical Observations
  3. GRB030328: Decay index
  4. GRB 030328: Optical observations
  5. GRB 030328: optical observations
  6. GRB 030329: Optical afterglow fading
  7. GRB 030329 follow-up
  8. GRB 030329: Optical afterglow candidate
  9. GRB 030329: OT candidate
  10. GRB 030329: Optical afterglow candidate
  11. GRB 030328: OT photometry
  12. GRB030328: optical spectroscopy at TNG
  13. GRB030328: optical photometry at the TNG
  14. VLT spectra of GRB 030328
  15. GRB 030328, optical spectroscopy
  16. GRB 030328, optical observations
  17. GRB 030328: Optical observations
  18. GRB 030328: Optical afterglow candidate
  19. GRB030323 optical observations
  20. GRB030324 optical observation
  21. GRB030131, BVRcIc field photometry
  22. Possible GRB030323 localized by INTEGRAL
  23. GRB030323: Detection on 2003/03/24
  24. GRB 030323: SARA Optical Observations
  25. GRB030324, optical observations
  26. GRB030324, optical observations
  27. GRB 030324: TAROT optical observations
  28. GRB030323: V, R, I photometry
  29. GRB 030324 (HETE #2641): Optical observations
  30. GRB030324, Optical Observations
  31. GRB030323: Upper limits from recent and historical observations.
  32. VLT/FORS2 spectra of GRB 030323
  33. GRB030323, optical observations
  34. GRB030324, BVRcIc field photometry
  35. GRB030323, possible optical counterpart
  36. GRB030323, BVRcIc field calibration
  37. GRB 030324 optical observations
  38. GRB 030320: Optical Observations
  39. GRB 030324, optical observations
  40. IPN triangulation of GRB030320
  41. GRB030226, addendum to GCN 1892
  42. IPN upper limit to a GRB associated with SN2003L
  43. GRB 030227: Optical limit at RIKEN
  44. GRB 030226 Optical observations
  45. GRB030226: Optical observations at Asiago
  46. IPN triangulation of GRB030306 (single small error box)
  47. IPN triangulation of GRB030306 (intense; annulus only so far)
  48. GRB 030226: Optical observations
  49. GRB030226: Analysis of Chandra data
  50. GRB 030227: Optical observations
  51. GRB030226, BVRc observations
  52. Chandra detection of the X-ray afterglow of GRB 030226
  53. GRB 030226, further optical/NIR imaging
  54. GRB030227, optical observations
  55. GRB 030226: Ic Observations
  56. GRB030227: Kiso optical upper limit
  57. GRB030227, BVRcIc field photometry
  58. GRB030226, BVRcIc field calibration
  59. GRB 030227 optical afterglow
  60. GRB 030228, optical observations
  61. GRB 030226: Steep Decline
  62. GRB 030227: Confirmed Optical Afterglow (S1-A)
  63. GRB 030226: R band polarimetric observations
  64. GRB 030226: Optical observations
  65. GRB 030227: fading of candidate optical afterglow 'S1-A'
  66. GRB030227:Optical observations
  67. GRB 20030226: Upper limits from recent and historical 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. GRB 030226 spectroscopy
  76. GRB030227: refined INTEGRAL position
  77. GRB030227 localized by INTEGRAL
  78. Possible break in the GRB 030226 light curve
  79. GRB 030226 : Predicted light curve
  80. GRB030226: optical observation
  81. GRB 030226: Confirmed decay index
  82. GRB030226: ESI spectroscopy
  83. GRB 030226 simultaneous optical observations
  84. Two absorption systems in GRB 030226
  85. GRB 030226, optical observations
  86. GRB030226: optical observations and refined redshift
  87. GRB030226: Optical decay index
  88. GRB 030226 Optical Spectra and R,I,z' Imaging
  89. GRB 030226, optical observations
  90. GRB 030226: Optical afterglow
  91. GRB030226: Candidate optical afterglow
  92. GRB 030217: Optical Observations at 4, 5, and 6 Days
  93. GRB030217: optical observations
  94. IPN triangulation of GRB030217 (small error box)
  95. IPN triangulation of GRB030215A and GRB030215B (annuli)
  96. GRB030115, WSRT radio observations - correction to GCN 1864
  97. GRB 030131: marginal optical detection
  98. GRB030115, WSRT radio observations
  99. IPN triangulation of GRB030206 (annulus)
  100. GRB 030204: Optical Observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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