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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"
  1. IPN triangulation of GRB030422 (two large error boxes)
  2. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  3. GRB030329, optical observation
  4. IPN triangulation of GRB030421 (annulus)
  5. MASTER:optical observations GRB030418
  6. MASTER:optical observations probable GRB030414
  7. GRB030329: 444 AAVSO Measurements
  8. IPN triangulation of GRB030419 (annulus)
  9. MASTER:optical observations GRB030416
  10. ROTSE-III prompt optical detections of GRB 030418
  11. GRB030418: Upper limits from recent and historical observations.
  12. GRB030418: Kiso near infrared observations
  13. GRB 030418: Optical afterglow
  14. GRB 030418: Finder for afterglow candidate
  15. GRB 030418: Optical afterglow candidate
  16. GRB 030329 OT position
  17. GRB030329: Optical Observations
  18. OT GRB 030329: early UBVRcIc spectral evolution
  19. GRB030329, UBVRI polarimetry, R-polarization
  20. GRB 030329: SARA Optical Observations
  21. OT GRB 030329: early spectrum
  22. GRB030329: VR Photometry at TNG
  23. GRB030324: Candidate Optical Afterglow (Erratum)
  24. GRB030324: Candidate Optical Afterglow
  25. IPN triangulation of GRB030414 (small error box)
  26. GRB 030413: Optical Observations
  27. GRB 030329 Rc observations
  28. IPN triangulation of GRB030413 (small error box)
  29. IPN triangulation of GRB030410 (annulus)
  30. Superluminal motion in GRB 030329 (Correction)
  31. Superluminal motion in GRB 030329
  32. GRB 030329 and SN 2003dh
  33. GRB030329, optical position
  34. GRB 030329 VLBA Observations
  35. CORRECTION TO IPN TRIANGULATION OF GRB050403
  36. IPN triangulation of GRB030406 (small error box)
  37. IPN triangulation of GRB050403 (small error box)
  38. IPN triangulation of GRB030403 (annulus)
  39. GRB 030329: BVRI photometry at Asiago
  40. GRB 030329, light curve flattens
  41. GRB 030329: VLT V-band photometry
  42. If the SN/GRB connection confirmed
  43. GRB 030329: Supernova Confirmed
  44. GRB030329: RTT150 optical observations
  45. GRB030329: Near Infrared Observations at Gunma
  46. GRB030329: HET spectroscopic monitoring
  47. Kiso observation of the GRB030329 at April 6
  48. GRB 030329, color evolution
  49. GRB030328, UBVRcIc field photometry
  50. GRB030329: Optical observcations
  51. GRB030329: BV photographic observations
  52. GRB 030329 Optical observations
  53. GRB 030329, color evolution
  54. GRB 030329: possible color change
  55. GRB030329: RTT150 optical observations
  56. GRB 030329: Supernova Spectrum Emerging
  57. GRB030329: Kiso B and R band observations
  58. GRB030329: RTT150 optical observation
  59. GRB030329: More AAVSO VR obs
  60. GRB030328: R upper limit after 6 hours by MASTER
  61. GRB 030329: BV photographic observations
  62. GRB 030329: SARA Optical Observations
  63. GRB 030329: SARA Optical Observations
  64. GRB030329, fading resumes
  65. GRB 030329, BVRI photometry
  66. GRB030329: Optical observations
  67. SDSS 0.5m PT observations of GRB030329 (correction)
  68. SDSS 0.5m PT observations of GRB030329
  69. GRB 030329, Optical observations
  70. GRB 030329, nearby galaxies
  71. GRB030329, cessation of fading
  72. GRB030329: final R-band light curve by MASTER
  73. GRB030329 - more 15 GHz radio data
  74. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  75. GRB 030329: Sub-millimeter detection
  76. GRB 030329: SARA Optical Observations
  77. GRB 030329: SARA Optical Observations
  78. OT GRB light curves and SN predictions
  79. GRB030329, optical observation
  80. GRB030329, optical observation
  81. GRB030329, new UBVRcIc field photometry
  82. GRB 030329, light curve and SN prediction
  83. GRB030329: optical observations at Tokyo Tech
  84. GRB 030329: optical observations
  85. GRB030329: multiple re-brightening phases
  86. GRB 030329, BRI photometry
  87. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  88. GRB 030329 , SPM optical observations
  89. GRB030329: Optical observations at Teramo
  90. GRB 030329: Radio observations at GMRT
  91. GRB030329: more 15GHz observations
  92. Further AAVSO V,B,R observations of GRB030329
  93. GRB 030329: Additional Mt. Laguna Optical Observations
  94. GRB 030329: SARA Optical Observations
  95. GRB 030329: Observations with ANDICAM
  96. GRB030329: Optical observations
  97. GRB030329: further optical photometry and evidence for a light curve discontinuity
  98. GRB 030329: Correction to GCN 2056
  99. GRB 030329: fitting parameters and re-brightening
  100. GRB 030329: KAIT optical photometry

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