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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"

32501 results found.

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

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