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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"

36155 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. Photometry of GRB030329 - Constant OT Magnitude
  6. GRB 030329, R-band observations
  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. 030331 NOT A GRB
  16. INTEGRAL GRB 030331
  17. GRB 030324: Optical and NIR Observations
  18. GRB 030328, optical photometry
  19. GRB030329: R band light curve by MASTER
  20. GRB030329 - Light curve flattening
  21. GRB 030329: SARA Optical Observations
  22. GRB 030324, optical search
  23. GRB030329 - near contemporaneous optical limits from CONCAM
  24. GRB 030329, optical observations
  25. GRB 030329: Light curve observed during the change of its slope.
  26. GRB030329, BVRcIc field photometry
  27. GRB030329, SPM optical observations
  28. GRB 030329: Optical Decay
  29. Redshift of GRB 030329
  30. GRB030329: ROTSE network observes steepening of decay curve
  31. GRB 030329, optical photometry
  32. GRB 030329: Optical decay and synthesis
  33. GRB 030329: Radio Observations
  34. GRB 030329, optical spectroscopy
  35. GRB 030329: still bright
  36. GRB 030329: Optical pre-Imaging
  37. GRB 030329: visual observations
  38. GRB 030329: Upper limit from 5.6 hours before trigger
  39. GRB030328: R optical observation
  40. GRB 030323: Gemini South VRI obsevations.
  41. GRB030329: Optical observations
  42. GRB 030329, R-band observations, supplement
  43. GRB030329:optical observations by MASTER
  44. GRB 030329: optical observations
  45. GRB 030329, R-band observations
  46. GRB 030329: OT B and R photometry, decline rate
  47. GRB030329: Upper limits from recent and historical observations.
  48. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  49. RXTE detection of GRB 030329 afterglow
  50. GRB 030329: Optical Afterglow Observations
  51. GRB 030329: precise position from Kyoto images
  52. GRB 030328 Optical Observations
  53. GRB 030328: Optical observations
  54. GRB 030328: optical observations
  55. GRB 030329: Optical afterglow fading
  56. GRB 030329 follow-up
  57. GRB 030329: Optical afterglow candidate
  58. GRB 030329: OT candidate
  59. GRB 030329: Optical afterglow candidate
  60. GRB 030328: OT photometry
  61. VLT spectra of GRB 030328
  62. GRB 030328, optical spectroscopy
  63. GRB 030328, optical observations
  64. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  65. GRB 030328: Optical observations
  66. Re: GRB 030328: Finding chart
  67. GRB 030328: Finding chart
  68. GRB 030328: Optical afterglow candidate
  69. GRB030131, BVRcIc field photometry
  70. Possible GRB030323 localized by INTEGRAL
  71. IPN triangulation of GRB030325 (final analysis)
  72. IPN triangulation of GRB030326 (single small error box)
  73. GRB 030323: SARA Optical Observations
  74. IPN triangulation of GRB030325 (single small error box)
  75. GRB030324, optical observations
  76. IPN triangulation of GRB030325 (two small error boxes)
  77. GRB 030324: TAROT optical observations
  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. GRB030324, BVRcIc field photometry
  88. GRB030323, possible optical counterpart
  89. GRB030323, BVRcIc field calibration
  90. GRB 030324 optical observations
  91. GRB 030320: Optical Observations
  92. GRB 030324, optical observations
  93. IPN triangulation of GRB030320B (annulus)
  94. IPN triangulation of GRB030320 (small error box)
  95. IPN triangulation of GRB030320
  96. Possible GRB 030320 localized by INTEGRAL
  97. IPN upper limit to a GRB associated with SN2003L
  98. IPN triangulation of GRB030317 (annulus)
  99. IPN triangulation of GRB030307 (annulus)
  100. GRB 030227: Optical limit at RIKEN

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