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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"

32488 results found.

  1. IPN triangulation of GRB030725 (=H2779; small error box)
  2. XRF030723 (=H2777): Second Epoch Magellan Observations
  3. GRB 030725: optical observations.
  4. GRB030725, optical transient observations
  5. XRF030723 Radio Observations
  6. XRF 030723: confirmation of fading optical counterpart
  7. XRF030723(=H2777): Chandra Observations
  8. XRF 030723: VLT spectra
  9. Magellan Observations of XRF030723 (=H2777)
  10. GRB030723: Upper limits from historical observations
  11. GRB030725, possible optical transient
  12. XRF030723: Palomar observations and proposed counterpart
  13. GRB030725 (=H2779): A Bright GRB Localized by HETE
  14. XRF030723: optical observations
  15. XRF030723 (= H2777): Chandra Observations Scheduled
  16. XRF030723, BVRcIc field photometry
  17. XRF030723, optical observations
  18. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  19. Konus-Wind detection of the bursts from SGR1806-20 region
  20. SGR 1806-20, submm observations
  21. RXTE PCA Observations of SGR1806-20 Region
  22. GRB030329: Subaru Optical Spectroscopy
  23. Triangulation of GRB030715 (single large error box)
  24. Triangulation of GRB030714 (single large error box)
  25. GRB030329: RTT150 optical observations
  26. GRBlog: Compilation of all GCN Circ. data
  27. GRB030706 triangulation (single large error box)
  28. GRB030329, optical observation in May
  29. IPN triangulation of GRB030626 (single large error box)
  30. GRB030418: R optical observations
  31. Final IPN error ellipse for GRB021206 (the polarized GRB)
  32. GRB 021206, Radio afterglow candidate
  33. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  34. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  35. GRB 030528: Optical Observations
  36. GRB 030528: tentative NIR counterpart
  37. GRB 030528, radio observations
  38. GRB030329, further radio observations at GMRT
  39. GRB030528, BVRI field photometry
  40. GRB030329, SPM optical observations
  41. GRB030528: Chandra TOO Planned
  42. GRB 030519B: optical observations.
  43. GRB 030329: optical observations
  44. GRB 030329/SN 2003dh: Jitter Episode
  45. GRB 030528, Teramo optical observation
  46. GRB 030528 Bisei optical observation
  47. GRB030528 (H2724): A long GRB localized by HETE
  48. GRB 030329: Correction to GCN 2254
  49. GRB 030329: Optical Observations
  50. GRB 030416: Optical Observations
  51. GRB030329, Optical observations
  52. GRB 030329/SN 2003dh: Possible increase in brightness
  53. GRB 030329: HST ACS Observations of the Host
  54. GRB 030329 Optical Observations
  55. GRB030329: XMM-Newton observation
  56. GRB030324: Further Observations of the Candidate Optical Afterglow
  57. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  58. IPN triangulation of GRB030519B=H2716 (small error box)
  59. GRB 030418: Second Epoch Optical Observations with Magellan
  60. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  61. HETE GRB030329, correction to Rc Observations in Loiano
  62. GRB 030329: Optical limit (contemporaneous imaging)
  63. GRB 030501: final TAROT limits
  64. IPN triangulation of GRB030509 (small errror box)
  65. IPN triangulation of GRB030509 - correction
  66. GRB030329: RTT150 optical observations
  67. GRB030329, BVRI photometry
  68. GRB030429, refiend optical brightness
  69. GRB 030329: Optical limit (contemporaneous photography)
  70. GRB030418, BVRcIc field photometry
  71. GRB 030429: Redshift of neighbor galaxy
  72. GRB030429, BVRcIc field photometry
  73. GRB030429: RTT150 optical obs., correction to GCN 2208
  74. GRB 030329: High-Resolution Spectroscopy of the Host
  75. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  76. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  77. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  78. GRB030429: RTT150 optical observations, a possible host galaxy
  79. GRB030329: RTT150 optical observations and upper limit for a host
  80. GRB030501, optical observation
  81. GRB030501 observation report
  82. GRB030501 triangulation (correction to GCN 2194)
  83. GRB030329: RTT150 optical observations and upper limit for a host
  84. GRB 030429: Radio Observations
  85. GRB 030429: redshift from VLT spectroscopy
  86. GRB 030429: IR photometry with IRSF/SIRIUS
  87. GRB030501B triangulation (single error box)
  88. GRB 030329 Optical Observations
  89. GRB030328, optical observation
  90. GRB 030329, BVRI photometry
  91. GRB030429: Optical Observations
  92. GRB030501: TAROT candidate afterglow present in archival images
  93. GRB 030501: TAROT possible candidate counterpart
  94. IPN triangulation of GRB030501 (IBIS event; annulus)
  95. GRB 030429: confirmation of afterglow candidate
  96. GRB030425: CrAO optical observation
  97. GRB 030329 Oprical observations in Rozhen observatory
  98. GRB 030324: Radio Observations
  99. GRB030329 observed as a sudden ionospheric disturbance (SID)
  100. GRB030329, SPM optical observations

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