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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"

32492 results found.

  1. GRB 030329: OT observations at Kanazawa
  2. GRB030329 15 GHz radio observation
  3. GRB 030329 RBO V Optical Observations
  4. GRB 030329, optical photometry
  5. GRB030329: Near Infrared Observations
  6. GRB 030324: Optical and NIR Observations
  7. GRB 030328, optical photometry
  8. GRB030329: R band light curve by MASTER
  9. GRB030329 - Light curve flattening
  10. GRB 030329: SARA Optical Observations
  11. GRB 030324, optical search
  12. GRB030329 - near contemporaneous optical limits from CONCAM
  13. GRB030329: R and B observations
  14. GRB 030329, optical observations
  15. GRB030329: Optical observations
  16. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  17. GRB030329a: detection by Konus-Wind
  18. GRB 030329: Light curve observed during the change of its slope.
  19. GRB030329, BVRcIc field photometry
  20. GRB030329, SPM optical observations
  21. GRB 030329: Optical Decay
  22. Redshift of GRB 030329
  23. GRB030329: ROTSE network observes steepening of decay curve
  24. GRB 030329, optical photometry
  25. GRB 030329: Optical decay and synthesis
  26. GRB030329 optical observations
  27. GRB030329: optical spectroscopy with the TNG
  28. GRB 030329: Radio Observations
  29. GRB 030329, optical spectroscopy
  30. GRB 030329: still bright
  31. GRB 030329: Optical pre-Imaging
  32. GRB 030329: visual observations
  33. GRB 030329: Upper limit from 5.6 hours before trigger
  34. GRB030328: R optical observation
  35. GRB030328: X-ray Afterglow Observed with Chandra
  36. GRB 030323: Gemini South VRI obsevations.
  37. GRB030329: Optical observations
  38. GRB030329:optical observations by MASTER
  39. GRB 030329: optical observations
  40. GRB 030329, R-band observations
  41. GRB 030329: OT B and R photometry, decline rate
  42. GRB030329: Upper limits from recent and historical observations.
  43. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  44. GRB 030329: Optical Afterglow Observations
  45. GRB 030329: precise position from Kyoto images
  46. GRB 030328 Optical Observations
  47. GRB030328: Decay index
  48. GRB 030328: Optical observations
  49. GRB 030328: optical observations
  50. GRB 030329: Optical afterglow fading
  51. GRB 030328: OT photometry
  52. GRB030328: optical spectroscopy at TNG
  53. GRB030328: optical photometry at the TNG
  54. VLT spectra of GRB 030328
  55. GRB 030328, optical spectroscopy
  56. GRB 030328, optical observations
  57. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  58. GRB 030328: Optical observations
  59. GRB 030328: Finding chart
  60. GRB030323 optical observations
  61. GRB030131, BVRcIc field photometry
  62. IPN triangulation of GRB030325 (final analysis)
  63. GRB030323: Detection on 2003/03/24
  64. GRB 030323: SARA Optical Observations
  65. IPN triangulation of GRB030325 (single small error box)
  66. GRB030324, optical observations
  67. GRB030324, optical observations
  68. GRB 030324: TAROT optical observations
  69. GRB030323: V, R, I photometry
  70. GRB 030324 (HETE #2641): Optical observations
  71. GRB030324, Optical Observations
  72. GRB030323: Upper limits from recent and historical observations.
  73. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  74. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  75. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  76. VLT/FORS2 spectra of GRB 030323
  77. GRB030323, ROTSE-III detection of possible optical counterpart
  78. GRB030323, optical observations
  79. GRB030323, possible optical counterpart
  80. GRB 030324 optical observations
  81. GRB 030320: Optical Observations
  82. IPN triangulation of GRB030320 (small error box)
  83. IPN triangulation of GRB030320
  84. GRB030226, addendum to GCN 1892
  85. IPN upper limit to a GRB associated with SN2003L
  86. GRB 030227: Optical limit at RIKEN
  87. GRB 030226 Optical observations
  88. IPN triangulation of GRB030306 (single small error box - REVISED)
  89. GRB030226: Optical observations at Asiago
  90. IPN triangulation of GRB030306 (two small error boxes)
  91. GRB 030226: Optical observations
  92. GRB030226: Analysis of Chandra data
  93. GRB 030227: Optical observations
  94. GRB030226, BVRc observations
  95. Chandra detection of the X-ray afterglow of GRB 030226
  96. GRB 030226, further optical/NIR imaging
  97. GRB 030226: Ic Observations
  98. GRB030227: Kiso optical upper limit
  99. GRB030227, BVRcIc field photometry
  100. GRB030226, BVRcIc field calibration

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