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

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