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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"

32508 results found.

  1. XRF030824: Second-epoch Palomar observations
  2. XRF030824: optical observations
  3. XRF030824: Palomar observations
  4. GRB030823: optical observation at Tokyo Tech
  5. RAPTOR observations of GRB030823
  6. IPN triangulation of GRB030821 (=H2814; refined error box)
  7. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  8. Summary of recent IPN and HETE detections of SGR bursts
  9. Clarification of GCN 2354 on SGR1806-20
  10. IPN detection of continued activity from SGR1806-20
  11. 030813 SGR event (Konus-Wind observation)
  12. SGR 1808-20 (=H2802): A Possible new SGR
  13. GRB 021206 Optical Observations
  14. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  15. IPN/HETE summary of recent bursts from SGR1806-20
  16. XRF 030723: Detection of a rebrightening in the optical afterglow
  17. GRB030725: Optical observations
  18. XRF030723, BVRcIc field photometry update
  19. GRB021206 optical counterpart upper limit
  20. XRF030723: Re-analysis of ROTSE-III early images
  21. IPN triangulation of GRB030725 (=H2779; small error box)
  22. XRF030723 (=H2777): Second Epoch Magellan Observations
  23. GRB 030725: optical observations.
  24. GRB030725, optical transient observations
  25. XRF030723 Radio Observations
  26. XRF 030723: confirmation of fading optical counterpart
  27. XRF030723(=H2777): Chandra Observations
  28. XRF 030723: VLT spectra
  29. Magellan Observations of XRF030723 (=H2777)
  30. GRB030723: Upper limits from historical observations
  31. GRB030725, possible optical transient
  32. XRF030723: Palomar observations and proposed counterpart
  33. GRB030725 (=H2779): A Bright GRB Localized by HETE
  34. XRF030723: optical observations
  35. XRF030723 (= H2777): Chandra Observations Scheduled
  36. XRF030723, BVRcIc field photometry
  37. XRF030723, optical observations
  38. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  39. Konus-Wind detection of the bursts from SGR1806-20 region
  40. SGR 1806-20, submm observations
  41. RXTE PCA Observations of SGR1806-20 Region
  42. GRB030329: Subaru Optical Spectroscopy
  43. Triangulation of GRB030715 (single large error box)
  44. Triangulation of GRB030714 (single large error box)
  45. GRB030329: RTT150 optical observations
  46. GRBlog: Compilation of all GCN Circ. data
  47. GRB030706 triangulation (single large error box)
  48. GRB030329, optical observation in May
  49. IPN triangulation of GRB030626 (single large error box)
  50. GRB030418: R optical observations
  51. Final IPN error ellipse for GRB021206 (the polarized GRB)
  52. GRB 021206, Radio afterglow candidate
  53. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  54. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  55. GRB 030528: Optical Observations
  56. GRB 030528: tentative NIR counterpart
  57. GRB 030528, radio observations
  58. GRB030329, further radio observations at GMRT
  59. GRB030528, BVRI field photometry
  60. GRB030329, SPM optical observations
  61. GRB030528: Chandra TOO Planned
  62. GRB 030519B: optical observations.
  63. GRB 030329: optical observations
  64. GRB 030329/SN 2003dh: Jitter Episode
  65. GRB 030528, Teramo optical observation
  66. GRB 030528 Bisei optical observation
  67. GRB030528 (H2724): A long GRB localized by HETE
  68. GRB 030329: Correction to GCN 2254
  69. GRB 030329: Optical Observations
  70. GRB 030416: Optical Observations
  71. GRB030329, Optical observations
  72. GRB 030329/SN 2003dh: Possible increase in brightness
  73. GRB 030329: HST ACS Observations of the Host
  74. GRB 030329 Optical Observations
  75. GRB030329: XMM-Newton observation
  76. GRB030324: Further Observations of the Candidate Optical Afterglow
  77. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  78. IPN triangulation of GRB030519B=H2716 (small error box)
  79. GRB 030418: Second Epoch Optical Observations with Magellan
  80. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  81. HETE GRB030329, correction to Rc Observations in Loiano
  82. GRB 030329: Optical limit (contemporaneous imaging)
  83. GRB 030501: final TAROT limits
  84. IPN triangulation of GRB030509 (small errror box)
  85. IPN triangulation of GRB030509 - correction
  86. GRB030329: RTT150 optical observations
  87. GRB030329, BVRI photometry
  88. GRB030429, refiend optical brightness
  89. GRB 030329: Optical limit (contemporaneous photography)
  90. GRB030418, BVRcIc field photometry
  91. GRB 030429: Redshift of neighbor galaxy
  92. GRB030429, BVRcIc field photometry
  93. GRB030429: RTT150 optical obs., correction to GCN 2208
  94. GRB 030329: High-Resolution Spectroscopy of the Host
  95. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  96. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  97. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  98. GRB030429: RTT150 optical observations, a possible host galaxy
  99. GRB030329: RTT150 optical observations and upper limit for a host
  100. GRB030501, optical observation

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