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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"

32541 results found.

  1. GRB030328: optical spectroscopy at TNG
  2. GRB030328: optical photometry at the TNG
  3. VLT spectra of GRB 030328
  4. GRB 030328, optical spectroscopy
  5. GRB 030328, optical observations
  6. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  7. GRB 030328: Optical observations
  8. GRB 030328: Finding chart
  9. GRB030323 optical observations
  10. GRB030131, BVRcIc field photometry
  11. IPN triangulation of GRB030325 (final analysis)
  12. GRB030323: Detection on 2003/03/24
  13. GRB 030323: SARA Optical Observations
  14. IPN triangulation of GRB030325 (single small error box)
  15. GRB030324, optical observations
  16. GRB030324, optical observations
  17. GRB 030324: TAROT optical observations
  18. GRB030323: V, R, I photometry
  19. GRB 030324 (HETE #2641): Optical observations
  20. GRB030324, Optical Observations
  21. GRB030323: Upper limits from recent and historical observations.
  22. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  23. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  24. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  25. VLT/FORS2 spectra of GRB 030323
  26. GRB030323, ROTSE-III detection of possible optical counterpart
  27. GRB030323, optical observations
  28. GRB030323, possible optical counterpart
  29. GRB 030324 optical observations
  30. GRB 030320: Optical Observations
  31. IPN triangulation of GRB030320 (small error box)
  32. IPN triangulation of GRB030320
  33. GRB030226, addendum to GCN 1892
  34. IPN upper limit to a GRB associated with SN2003L
  35. GRB 030227: Optical limit at RIKEN
  36. GRB 030226 Optical observations
  37. IPN triangulation of GRB030306 (single small error box - REVISED)
  38. GRB030226: Optical observations at Asiago
  39. IPN triangulation of GRB030306 (two small error boxes)
  40. GRB 030226: Optical observations
  41. GRB030226: Analysis of Chandra data
  42. GRB 030227: Optical observations
  43. GRB030226, BVRc observations
  44. Chandra detection of the X-ray afterglow of GRB 030226
  45. GRB 030226, further optical/NIR imaging
  46. GRB 030226: Ic Observations
  47. GRB030227: Kiso optical upper limit
  48. GRB030227, BVRcIc field photometry
  49. GRB030226, BVRcIc field calibration
  50. GRB 030227 optical afterglow
  51. GRB 030226: Steep Decline
  52. GRB 030227: Confirmed Optical Afterglow (S1-A)
  53. GRB 030226: R band polarimetric observations
  54. GRB 030226: Optical observations
  55. GRB 030227: fading of candidate optical afterglow 'S1-A'
  56. GRB030227:Optical observations
  57. GRB 20030226: Upper limits from recent and historical observations
  58. GRB 030227, possible optical counterpart of XMM-Newton source
  59. GRB030227 - faint tentative OT candidate
  60. GRB 030226, optical observations
  61. XMM-Newton observation of GRB030227
  62. GRB 030227: Kyoto optical observation
  63. GRB 030226, optical light curve
  64. GRB 030226 spectroscopy
  65. Possible break in the GRB 030226 light curve
  66. GRB030226: optical observation
  67. GRB 030226: Confirmed decay index
  68. GRB030226: ESI spectroscopy
  69. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  70. Two absorption systems in GRB 030226
  71. GRB 030226, optical observations
  72. GRB030226: optical observations and refined redshift
  73. GRB 030226, optical observations
  74. GRB 030226: Optical afterglow
  75. GRB 030217: Optical Observations at 4, 5, and 6 Days
  76. GRB: Non-Referencing of GCN Circulars.
  77. GRB030217: optical observations
  78. IPN triangulation of GRB030217 (small error box)
  79. GRB030115, WSRT radio observations - correction to GCN 1864
  80. GRB 030131: marginal optical detection
  81. GCN/INTEGRAL Mistake Fixed
  82. GRB 030204: Optical Observations
  83. GRB030204 field photometry
  84. GRB020819: Kiso R and I band observations
  85. GRB 030204: Correction to GCN 1856
  86. GRB030131: Candidate Optical Afterglow
  87. GRB 030115: Optical Observations
  88. GRB 030204, optical observations
  89. GRB 030131, optical observations
  90. GRB030131: Kiso optical limit for corrected position
  91. GRB030131: Optical limits for corrected position
  92. GRB 030131: afterglow candidate
  93. GRB 030115, late-time optical observations
  94. Type Ic SN2003L (SN/GRB?), optical spectrum
  95. GRB 020819: Host galaxy at Radio Position
  96. IPN triangulation of GRB030131 - CORRECTION
  97. IPN triangulation of GRB030131
  98. GRB030131: Optical limit
  99. GRB 030131 optical observations
  100. GRB030131: refined position

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