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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. GRB 030329, the review of the sky area in plate archive (1950-1998)
  2. GRB 030329: Spectral Evolution of SN 2003dh
  3. Optical Observations of GRB 030418 with Magellan
  4. GRB 030329: optical spectropolarimetry at VLT
  5. IPN triangulation of GRB030422C (annulus)
  6. IPN triangulation of GRB030422B (annulus)
  7. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  8. GRB030329: optical polarization
  9. IPN triangulation of GRB030422 (two large error boxes)
  10. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  11. GRB030329, optical observation
  12. IPN triangulation of GRB030421 (annulus)
  13. MASTER:optical observations GRB030418
  14. MASTER:optical observations probable GRB030414
  15. GRB030329: 444 AAVSO Measurements
  16. IPN triangulation of GRB030419 (annulus)
  17. MASTER:optical observations GRB030416
  18. ROTSE-III prompt optical detections of GRB 030418
  19. GRB030418: Upper limits from recent and historical observations.
  20. GRB030418: Kiso near infrared observations
  21. GRB 030418: Optical afterglow
  22. GRB 030418: Finder for afterglow candidate
  23. GRB 030418: Optical afterglow candidate
  24. GRB 030329 OT position
  25. GRB030329: Optical Observations
  26. OT GRB 030329: early UBVRcIc spectral evolution
  27. GRB030329, UBVRI polarimetry, R-polarization
  28. GRB 030329: SARA Optical Observations
  29. OT GRB 030329: early spectrum
  30. GRB030329: VR Photometry at TNG
  31. GRB030324: Candidate Optical Afterglow (Erratum)
  32. GRB030324: Candidate Optical Afterglow
  33. IPN triangulation of GRB030414 (small error box)
  34. GRB 030413: Optical Observations
  35. GRB 030329 Rc observations
  36. IPN triangulation of GRB030413 (small error box)
  37. IPN triangulation of GRB030410 (annulus)
  38. Superluminal motion in GRB 030329 (Correction)
  39. Superluminal motion in GRB 030329
  40. GRB 030329 and SN 2003dh
  41. GRB030329, optical position
  42. GRB 030329 VLBA Observations
  43. CORRECTION TO IPN TRIANGULATION OF GRB050403
  44. IPN triangulation of GRB030406 (small error box)
  45. IPN triangulation of GRB050403 (small error box)
  46. IPN triangulation of GRB030403 (annulus)
  47. GRB 030329: BVRI photometry at Asiago
  48. GRB 030329, light curve flattens
  49. GRB 030329: VLT V-band photometry
  50. If the SN/GRB connection confirmed
  51. GRB 030329: Supernova Confirmed
  52. GRB030329: RTT150 optical observations
  53. GRB030329: Near Infrared Observations at Gunma
  54. GRB030329: HET spectroscopic monitoring
  55. Kiso observation of the GRB030329 at April 6
  56. GRB 030329, color evolution
  57. GRB030328, UBVRcIc field photometry
  58. GRB030329: Optical observcations
  59. GRB030329: BV photographic observations
  60. GRB 030329 Optical observations
  61. GRB 030329, color evolution
  62. GRB 030329: possible color change
  63. GRB030329: RTT150 optical observations
  64. GRB 030329: Supernova Spectrum Emerging
  65. GRB030329: Kiso B and R band observations
  66. GRB030329: RTT150 optical observation
  67. GRB030329: More AAVSO VR obs
  68. GRB030328: R upper limit after 6 hours by MASTER
  69. GRB 030329: BV photographic observations
  70. GRB 030329: SARA Optical Observations
  71. GRB 030329: SARA Optical Observations
  72. GRB030329, fading resumes
  73. GRB 030329, BVRI photometry
  74. GRB030329: Optical observations
  75. SDSS 0.5m PT observations of GRB030329 (correction)
  76. SDSS 0.5m PT observations of GRB030329
  77. GRB 030329, Optical observations
  78. GRB 030329, nearby galaxies
  79. GRB030329, cessation of fading
  80. GRB030329: final R-band light curve by MASTER
  81. GRB030329 - more 15 GHz radio data
  82. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  83. GRB 030329: Sub-millimeter detection
  84. GRB 030329: SARA Optical Observations
  85. GRB 030329: SARA Optical Observations
  86. OT GRB light curves and SN predictions
  87. GRB030329, optical observation
  88. GRB030329, optical observation
  89. GRB030329, new UBVRcIc field photometry
  90. GRB 030329, light curve and SN prediction
  91. GRB030329: optical observations at Tokyo Tech
  92. GRB 030329: optical observations
  93. GRB030329: multiple re-brightening phases
  94. GRB 030329, BRI photometry
  95. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  96. GRB 030329 , SPM optical observations
  97. GRB030329: Optical observations at Teramo
  98. GRB 030329: Radio observations at GMRT
  99. GRB030329: more 15GHz observations
  100. Further AAVSO V,B,R observations of GRB030329

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