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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"

32494 results found.

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

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