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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"

32532 results found.

  1. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  2. IPN triangulation of GRB030519B=H2716 (small error box)
  3. GRB 030418: Second Epoch Optical Observations with Magellan
  4. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  5. HETE GRB030329, correction to Rc Observations in Loiano
  6. GRB 030329: Optical limit (contemporaneous imaging)
  7. GRB 030501: final TAROT limits
  8. IPN triangulation of GRB030509 (small errror box)
  9. IPN triangulation of GRB030509 - correction
  10. GRB030329: RTT150 optical observations
  11. GRB030329, BVRI photometry
  12. GRB030429, refiend optical brightness
  13. GRB 030329: Optical limit (contemporaneous photography)
  14. GRB030418, BVRcIc field photometry
  15. GRB 030429: Redshift of neighbor galaxy
  16. GRB030429, BVRcIc field photometry
  17. GRB030429: RTT150 optical obs., correction to GCN 2208
  18. GRB 030329: High-Resolution Spectroscopy of the Host
  19. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  20. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  21. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  22. GRB030429: RTT150 optical observations, a possible host galaxy
  23. GRB030329: RTT150 optical observations and upper limit for a host
  24. GRB030501, optical observation
  25. GRB030501 observation report
  26. GRB030501 triangulation (correction to GCN 2194)
  27. GRB030329: RTT150 optical observations and upper limit for a host
  28. GRB 030429: Radio Observations
  29. GRB 030429: redshift from VLT spectroscopy
  30. GRB 030429: IR photometry with IRSF/SIRIUS
  31. GRB030501B triangulation (single error box)
  32. GRB 030329 Optical Observations
  33. GRB030328, optical observation
  34. GRB 030329, BVRI photometry
  35. GRB030429: Optical Observations
  36. GRB030501: TAROT candidate afterglow present in archival images
  37. GRB 030501: TAROT possible candidate counterpart
  38. IPN triangulation of GRB030501 (IBIS event; annulus)
  39. GRB 030429: confirmation of afterglow candidate
  40. GRB030425: CrAO optical observation
  41. GRB 030329 Oprical observations in Rozhen observatory
  42. GRB 030324: Radio Observations
  43. GRB030329 observed as a sudden ionospheric disturbance (SID)
  44. GRB030329, SPM optical observations
  45. GRB 030329, the review of the sky area in plate archive (1950-1998)
  46. GRB 030329: Spectral Evolution of SN 2003dh
  47. GRB 030329: optical spectropolarimetry at VLT
  48. GRB030329: optical polarization
  49. GRB030329, optical observation
  50. GRB030329: 444 AAVSO Measurements
  51. ROTSE-III prompt optical detections of GRB 030418
  52. GRB030418: Upper limits from recent and historical observations.
  53. GRB 030418: Optical afterglow
  54. GRB 030418: Finder for afterglow candidate
  55. GRB 030329 OT position
  56. GRB030329: Optical Observations
  57. OT GRB 030329: early UBVRcIc spectral evolution
  58. GRB030329, UBVRI polarimetry, R-polarization
  59. GRB 030329: SARA Optical Observations
  60. OT GRB 030329: early spectrum
  61. GRB030329: VR Photometry at TNG
  62. GRB030324: Candidate Optical Afterglow
  63. GRB 030413: Optical Observations
  64. GRB 030329 Rc observations
  65. Superluminal motion in GRB 030329 (Correction)
  66. Superluminal motion in GRB 030329
  67. GRB 030329 and SN 2003dh
  68. GRB030329, optical position
  69. GRB 030329 VLBA Observations
  70. GRB 030329: BVRI photometry at Asiago
  71. GRB 030329, light curve flattens
  72. GRB 030329: VLT V-band photometry
  73. If the SN/GRB connection confirmed
  74. GRB 030329: Supernova Confirmed
  75. GRB030329: RTT150 optical observations
  76. GRB030329: Near Infrared Observations at Gunma
  77. GRB030329: HET spectroscopic monitoring
  78. GRB 030329, color evolution
  79. GRB030328, UBVRcIc field photometry
  80. GRB030329: Optical observcations
  81. GRB030329: BV photographic observations
  82. GRB 030329 Optical observations
  83. GRB 030329, color evolution
  84. GRB 030329: possible color change
  85. GRB030329: RTT150 optical observations
  86. GRB 030329: Supernova Spectrum Emerging
  87. GRB030329: RTT150 optical observation
  88. GRB030329: More AAVSO VR obs
  89. GRB030328: R upper limit after 6 hours by MASTER
  90. GRB 030329: BV photographic observations
  91. GRB 030329: SARA Optical Observations
  92. GRB 030329: SARA Optical Observations
  93. GRB030329, fading resumes
  94. GRB 030329, BVRI photometry
  95. GRB030329: Optical observations
  96. SDSS 0.5m PT observations of GRB030329 (correction)
  97. SDSS 0.5m PT observations of GRB030329
  98. GRB 030329, Optical observations
  99. GRB 030329, nearby galaxies
  100. GRB030329, cessation of fading

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