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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"

19570 results found.

  1. GRB030725, possible optical transient
  2. XRF030723: Palomar observations and proposed counterpart
  3. XRF030723, BVRcIc field photometry correction
  4. XRF030723, ROTSE-III Early Observations
  5. XRF030723, BVRcIc field photometry
  6. XRF 030723, optical observations
  7. XRF030723, optical observations
  8. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  9. SGR 1806-20, submm observations
  10. RXTE PCA Observations of SGR1806-20 Region
  11. GRB030329: Subaru Optical Spectroscopy
  12. GRB030329, optical observation in May
  13. IPN triangulation of GRB030626 (single large error box)
  14. IPN triangulation of GRB030626 (two large error boxes)
  15. HETE detection of burst from SGR1806-20
  16. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  17. IPN triangulation of GRB030606 (two alternate error boxes)
  18. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  19. GRB 030528: tentative NIR counterpart
  20. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  21. GRB030528, BVRI field photometry
  22. GRB030329, SPM optical observations
  23. GRB030528(=H2724): Revised SXC Localization
  24. GRB 030528 Bisei optical observation
  25. GRB030528 (H2724): A long GRB localized by HETE
  26. GRB 030528 (=H2724) Kyoto optical observation
  27. GRB030329, Optical observations
  28. GRB 030329 Optical Observations
  29. GRB 021004: HST observations
  30. GRB030324: Further Observations of the Candidate Optical Afterglow
  31. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  32. HETE GRB030329, correction to Rc Observations in Loiano
  33. GRB 030329: Optical limit (contemporaneous imaging)
  34. IPN triangulation of GRB030509 (small errror box)
  35. IPN triangulation of GRB030509 - correction
  36. IPN triangulation of GRB030509 (single error box)
  37. GRB030429, refiend optical brightness
  38. GRB030418, BVRcIc field photometry
  39. GRB030429, BVRcIc field photometry
  40. GRB030329: RTT150 optical observations and upper limit for a host
  41. GRB 030429: redshift from VLT spectroscopy
  42. GRB030501: TAROT candidate afterglow present in archival images
  43. IPN triangulation of GRB030501B (annulus)
  44. GRB 030429: confirmation of afterglow candidate
  45. GRB 030329 Oprical observations in Rozhen observatory
  46. GRB030329, SPM optical observations
  47. GRB 030329, the review of the sky area in plate archive (1950-1998)
  48. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  49. GRB030329: optical polarization
  50. MASTER:optical observations GRB030418
  51. MASTER:optical observations probable GRB030414
  52. GRB030418: Upper limits from recent and historical observations.
  53. GRB030418: Kiso near infrared observations
  54. GRB030329: Optical Observations
  55. GRB 030329: SARA Optical Observations
  56. OT GRB 030329: early spectrum
  57. IPN triangulation of GRB030414 (small error box)
  58. GRB 030329 and SN 2003dh
  59. GRB030329, optical position
  60. GRB 030329 VLBA Observations
  61. GRB 030329, light curve flattens
  62. Kiso observation of the GRB030329 at April 6
  63. GRB 030329, color evolution
  64. GRB030328, UBVRcIc field photometry
  65. GRB 030329 Optical observations
  66. GRB 030329, color evolution
  67. GRB030329: Kiso B and R band observations
  68. SDSS 0.5m PT observations of GRB030329 (correction)
  69. SDSS 0.5m PT observations of GRB030329
  70. GRB030329: final R-band light curve by MASTER
  71. GRB030329, new UBVRcIc field photometry
  72. GRB 030329 , SPM optical observations
  73. GRB030329: Optical observations at Teramo
  74. GRB 030329: Radio observations at GMRT
  75. GRB 030329: Additional Mt. Laguna Optical Observations
  76. GRB 030329: Observations with ANDICAM
  77. GRB 030329: optical observations
  78. GRB 030324: Optical and NIR Observations
  79. GRB030329: R band light curve by MASTER
  80. GRB030329 - Light curve flattening
  81. GRB 030324, optical search
  82. GRB 030329, optical observations
  83. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  84. GRB030329, BVRcIc field photometry
  85. GRB030329, SPM optical observations
  86. GRB 030329, optical photometry
  87. GRB030329 optical observations
  88. GRB 030329: Optical pre-Imaging
  89. GRB 030329: visual observations
  90. GRB 030329: Upper limit from 5.6 hours before trigger
  91. GRB030328: X-ray Afterglow Observed with Chandra
  92. GRB 030329, R-band observations
  93. GRB030329: Upper limits from recent and historical observations.
  94. GRB 030329: Optical Afterglow Observations
  95. GRB 030329: precise position from Kyoto images
  96. GRB 030328: Optical observations
  97. GRB 030328: optical observations
  98. GRB 030329: Optical afterglow fading
  99. GRB 030328: OT photometry
  100. GRB030328: optical photometry at the TNG

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