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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"

32500 results found.

  1. GRB 030329, optical spectroscopy
  2. GRB 030329: fading X-ray afterglow with RXTE
  3. GRB 030329: optical photometry
  4. GRB030329: Optical observations
  5. Photometry of GRB030329 - Constant OT Magnitude
  6. GRB 030329, R-band light curve
  7. GRB 030329: further optical observations
  8. GRB030329 - OT brightens
  9. GRB 030329: OT observations at Kanazawa
  10. GRB030329 15 GHz radio observation
  11. GRB 030329 RBO V Optical Observations
  12. GRB 030329, optical photometry
  13. GRB030329: Near Infrared Observations
  14. GRB 030324: Optical and NIR Observations
  15. GRB 030328, optical photometry
  16. GRB030329: R band light curve by MASTER
  17. GRB030329 - Light curve flattening
  18. GRB 030329: SARA Optical Observations
  19. GRB 030324, optical search
  20. GRB030329 - near contemporaneous optical limits from CONCAM
  21. GRB030329: R and B observations
  22. GRB 030329, optical observations
  23. GRB030329: Optical observations
  24. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  25. GRB030329a: detection by Konus-Wind
  26. GRB 030329: Light curve observed during the change of its slope.
  27. GRB030329, BVRcIc field photometry
  28. GRB030329, SPM optical observations
  29. GRB 030329: Optical Decay
  30. Redshift of GRB 030329
  31. GRB030329: ROTSE network observes steepening of decay curve
  32. GRB 030329, optical photometry
  33. GRB 030329: Optical decay and synthesis
  34. GRB030329 optical observations
  35. GRB030329: optical spectroscopy with the TNG
  36. GRB 030329: Radio Observations
  37. GRB 030329, optical spectroscopy
  38. GRB 030329: still bright
  39. GRB 030329: Optical pre-Imaging
  40. GRB 030329: visual observations
  41. GRB 030329: Upper limit from 5.6 hours before trigger
  42. GRB030328: R optical observation
  43. GRB030328: X-ray Afterglow Observed with Chandra
  44. GRB 030323: Gemini South VRI obsevations.
  45. GRB030329: Optical observations
  46. GRB030329:optical observations by MASTER
  47. GRB 030329: optical observations
  48. GRB 030329, R-band observations
  49. GRB 030329: OT B and R photometry, decline rate
  50. GRB030329: Upper limits from recent and historical observations.
  51. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  52. GRB 030329: Optical Afterglow Observations
  53. GRB 030329: precise position from Kyoto images
  54. GRB 030328 Optical Observations
  55. GRB030328: Decay index
  56. GRB 030328: Optical observations
  57. GRB 030328: optical observations
  58. GRB 030329: Optical afterglow fading
  59. GRB 030328: OT photometry
  60. GRB030328: optical spectroscopy at TNG
  61. GRB030328: optical photometry at the TNG
  62. VLT spectra of GRB 030328
  63. GRB 030328, optical spectroscopy
  64. GRB 030328, optical observations
  65. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  66. GRB 030328: Optical observations
  67. GRB 030328: Finding chart
  68. GRB030323 optical observations
  69. GRB030131, BVRcIc field photometry
  70. IPN triangulation of GRB030325 (final analysis)
  71. GRB030323: Detection on 2003/03/24
  72. GRB 030323: SARA Optical Observations
  73. IPN triangulation of GRB030325 (single small error box)
  74. GRB030324, optical observations
  75. GRB030324, optical observations
  76. GRB 030324: TAROT optical observations
  77. GRB030323: V, R, I photometry
  78. GRB 030324 (HETE #2641): Optical observations
  79. GRB030324, Optical Observations
  80. GRB030323: Upper limits from recent and historical observations.
  81. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  82. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  83. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  84. VLT/FORS2 spectra of GRB 030323
  85. GRB030323, ROTSE-III detection of possible optical counterpart
  86. GRB030323, optical observations
  87. GRB030323, possible optical counterpart
  88. GRB 030324 optical observations
  89. GRB 030320: Optical Observations
  90. IPN triangulation of GRB030320 (small error box)
  91. IPN triangulation of GRB030320
  92. GRB030226, addendum to GCN 1892
  93. IPN upper limit to a GRB associated with SN2003L
  94. GRB 030227: Optical limit at RIKEN
  95. GRB 030226 Optical observations
  96. IPN triangulation of GRB030306 (single small error box - REVISED)
  97. GRB030226: Optical observations at Asiago
  98. IPN triangulation of GRB030306 (two small error boxes)
  99. GRB 030226: Optical observations
  100. GRB030226: Analysis of Chandra data

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