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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"

41192 results found.

  1. XRF030723(=H2777): Chandra Observations
  2. XRF 030723: VLT spectra
  3. Magellan Observations of XRF030723 (=H2777)
  4. GRB030723: Upper limits from historical observations
  5. GRB030725, possible optical transient
  6. XRF030723: Palomar observations and proposed counterpart
  7. GRB030725 (=H2779): A Bright GRB Localized by HETE
  8. XRF030723: optical observations
  9. XRF030723 (= H2777): Chandra Observations Scheduled
  10. XRF030723, BVRcIc field photometry
  11. XRF 030723, optical observations
  12. XRF030723, optical observations
  13. XRF 030723, optical observations
  14. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  15. GRB030723, optical observations
  16. Konus-Wind detection of the bursts from SGR1806-20 region
  17. SGR 1806-20, submm observations
  18. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  19. RXTE PCA Observations of SGR1806-20 Region
  20. GRB030329: Subaru Optical Spectroscopy
  21. Triangulation of GRB030715 (single large error box)
  22. Triangulation of GRB030714 (single large error box)
  23. IPN triangulation of GRB030714 (two large error boxes)
  24. IPN triangulation of GRB030715 (two large error boxes)
  25. GRB030329: RTT150 optical observations
  26. GRBlog: Compilation of all GCN Circ. data
  27. IPN detection of renewed activity from SGR1806-20
  28. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  29. GRB030329, optical observation in May
  30. IPN triangulation of GRB030626 (two large error boxes)
  31. GRB030329: second XMM-Newton observation
  32. GRB030418: R optical observations
  33. HETE detection of burst from SGR1806-20
  34. GRB030329 -- RATAN-600 data in April-May
  35. Final IPN error ellipse for GRB021206 (the polarized GRB)
  36. GRB 021206, Radio afterglow candidate
  37. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  38. IPN triangulation of GRB030607 (annulus)
  39. IPN triangulation of GRB030606 (two alternate error boxes)
  40. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  41. GRB 030528: Optical Observations
  42. GRB 030528: tentative NIR counterpart
  43. GRB 030528, radio observations
  44. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  45. GRB030329, further radio observations at GMRT
  46. GRB030528, BVRI field photometry
  47. GRB030329, SPM optical observations
  48. GRB030528: Chandra TOO Planned
  49. GRB 030519B: optical observations.
  50. MASTER: optical observation GRB030601
  51. GRB030528(=H2724): Revised SXC Localization
  52. GRB 030329: optical observations
  53. GRB 030329/SN 2003dh: Jitter Episode
  54. GRB 030528, Teramo optical observation
  55. GRB 030528 Bisei optical observation
  56. GRB030528 (H2724): A long GRB localized by HETE
  57. GRB 030329: Correction to GCN 2254
  58. GRB 030329: Optical Observations
  59. GRB 030528: Optical observations at RIKEN
  60. GRB 030528 (=H2724) Kyoto optical observation
  61. IPN triangulation of GRB030523B (annulus)
  62. GRB 030416: Optical Observations
  63. GRB 030329: optical photometry at various french observatories
  64. GRB 030329: optical photometry at Belesta observatory (France)
  65. GRB030329, Optical observations
  66. GRB 030329/SN 2003dh: Possible increase in brightness
  67. GRB 030329: HST ACS Observations of the Host
  68. GRB 030329 Optical Observations
  69. GRB030329: XMM-Newton observation
  70. GRB 021004: HST observations
  71. GRB030324: Further Observations of the Candidate Optical Afterglow
  72. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  73. GRB 030418: Second Epoch Optical Observations with Magellan
  74. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  75. IPN triangulation of GRB030518B (annulus)
  76. GRB 030329: Optical limit (contemporaneous imaging)
  77. IPN triangulation of GRB030509 (small errror box)
  78. GRB030329: RTT150 optical observations
  79. GRB030329, BVRI photometry
  80. GRB030429, refiend optical brightness
  81. GRB 030329: Optical limit (contemporaneous photography)
  82. GRB030418, BVRcIc field photometry
  83. GRB 030429: Redshift of neighbor galaxy
  84. GRB030429, BVRcIc field photometry
  85. GRB030429: RTT150 optical obs., correction to GCN 2208
  86. GRB 030329: High-Resolution Spectroscopy of the Host
  87. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  88. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  89. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  90. GRB030429: RTT150 optical observations, a possible host galaxy
  91. GRB030329: RTT150 optical observations and upper limit for a host
  92. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  93. GRB030501, optical observation
  94. GRB030501 observation report
  95. GRB030329: RTT150 optical observations and upper limit for a host
  96. GRB 030429: Radio Observations
  97. GRB 030429: redshift from VLT spectroscopy
  98. GRB 030429: IR photometry with IRSF/SIRIUS
  99. GRB 030329 Optical Observations
  100. GRB030328, optical observation

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