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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"

32489 results found.

  1. GRB 030329, optical photometry
  2. GRB030329: Near Infrared Observations
  3. GRB 030324: Optical and NIR Observations
  4. GRB 030328, optical photometry
  5. GRB030329: R band light curve by MASTER
  6. GRB030329 - Light curve flattening
  7. GRB 030329: SARA Optical Observations
  8. GRB 030324, optical search
  9. GRB030329 - near contemporaneous optical limits from CONCAM
  10. GRB030329: R and B observations
  11. GRB 030329, optical observations
  12. GRB030329: Optical observations
  13. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  14. GRB030329a: detection by Konus-Wind
  15. GRB 030329: Light curve observed during the change of its slope.
  16. GRB030329, BVRcIc field photometry
  17. GRB030329, SPM optical observations
  18. GRB 030329: Optical Decay
  19. Redshift of GRB 030329
  20. GRB030329: ROTSE network observes steepening of decay curve
  21. GRB 030329, optical photometry
  22. GRB 030329: Optical decay and synthesis
  23. GRB030329 optical observations
  24. GRB030329: optical spectroscopy with the TNG
  25. GRB 030329: Radio Observations
  26. GRB 030329, optical spectroscopy
  27. GRB 030329: still bright
  28. GRB 030329: Optical pre-Imaging
  29. GRB 030329: visual observations
  30. GRB 030329: Upper limit from 5.6 hours before trigger
  31. GRB030328: R optical observation
  32. GRB030328: X-ray Afterglow Observed with Chandra
  33. GRB 030323: Gemini South VRI obsevations.
  34. GRB030329: Optical observations
  35. GRB030329:optical observations by MASTER
  36. GRB 030329: optical observations
  37. GRB 030329, R-band observations
  38. GRB 030329: OT B and R photometry, decline rate
  39. GRB030329: Upper limits from recent and historical observations.
  40. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  41. GRB 030329: Optical Afterglow Observations
  42. GRB 030329: precise position from Kyoto images
  43. GRB 030328 Optical Observations
  44. GRB030328: Decay index
  45. GRB 030328: Optical observations
  46. GRB 030328: optical observations
  47. GRB 030329: Optical afterglow fading
  48. GRB 030328: OT photometry
  49. GRB030328: optical spectroscopy at TNG
  50. GRB030328: optical photometry at the TNG
  51. VLT spectra of GRB 030328
  52. GRB 030328, optical spectroscopy
  53. GRB 030328, optical observations
  54. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  55. GRB 030328: Optical observations
  56. GRB 030328: Finding chart
  57. GRB030323 optical observations
  58. GRB030131, BVRcIc field photometry
  59. IPN triangulation of GRB030325 (final analysis)
  60. GRB030323: Detection on 2003/03/24
  61. GRB 030323: SARA Optical Observations
  62. IPN triangulation of GRB030325 (single small error box)
  63. GRB030324, optical observations
  64. GRB030324, optical observations
  65. GRB 030324: TAROT optical observations
  66. GRB030323: V, R, I photometry
  67. GRB 030324 (HETE #2641): Optical observations
  68. GRB030324, Optical Observations
  69. GRB030323: Upper limits from recent and historical observations.
  70. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  71. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  72. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  73. VLT/FORS2 spectra of GRB 030323
  74. GRB030323, ROTSE-III detection of possible optical counterpart
  75. GRB030323, optical observations
  76. GRB030323, possible optical counterpart
  77. GRB 030324 optical observations
  78. GRB 030320: Optical Observations
  79. IPN triangulation of GRB030320 (small error box)
  80. IPN triangulation of GRB030320
  81. GRB030226, addendum to GCN 1892
  82. IPN upper limit to a GRB associated with SN2003L
  83. GRB 030227: Optical limit at RIKEN
  84. GRB 030226 Optical observations
  85. IPN triangulation of GRB030306 (single small error box - REVISED)
  86. GRB030226: Optical observations at Asiago
  87. IPN triangulation of GRB030306 (two small error boxes)
  88. GRB 030226: Optical observations
  89. GRB030226: Analysis of Chandra data
  90. GRB 030227: Optical observations
  91. GRB030226, BVRc observations
  92. Chandra detection of the X-ray afterglow of GRB 030226
  93. GRB 030226, further optical/NIR imaging
  94. GRB 030226: Ic Observations
  95. GRB030227: Kiso optical upper limit
  96. GRB030227, BVRcIc field photometry
  97. GRB030226, BVRcIc field calibration
  98. GRB 030227 optical afterglow
  99. GRB 030226: Steep Decline
  100. GRB 030227: Confirmed Optical Afterglow (S1-A)

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