Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

15987 results found.

  1. XRF030723(=H2777): Chandra Observations
  2. Magellan Observations of XRF030723 (=H2777)
  3. GRB030723: Upper limits from historical observations
  4. GRB030725, possible optical transient
  5. XRF030723: Palomar observations and proposed counterpart
  6. GRB030725 (=H2779): A Bright GRB Localized by HETE
  7. XRF030723: optical observations
  8. XRF030723 (= H2777): Chandra Observations Scheduled
  9. XRF030723, BVRcIc field photometry
  10. XRF 030723, optical observations
  11. XRF030723, optical observations
  12. XRF 030723, optical observations
  13. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  14. GRB030723, optical observations
  15. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  16. GRB030329: Subaru Optical Spectroscopy
  17. GRB030329: RTT150 optical observations
  18. GRBlog: Compilation of all GCN Circ. data
  19. GRB030329, optical observation in May
  20. GRB030418: R optical observations
  21. HETE detection of burst from SGR1806-20
  22. GRB030329 -- RATAN-600 data in April-May
  23. GRB 021206, Radio afterglow candidate
  24. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  25. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  26. GRB 030528: Optical Observations
  27. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  28. GRB030329, SPM optical observations
  29. GRB 030519B: optical observations.
  30. MASTER: optical observation GRB030601
  31. GRB030528(=H2724): Revised SXC Localization
  32. GRB 030329: optical observations
  33. GRB 030528, Teramo optical observation
  34. GRB 030528 Bisei optical observation
  35. GRB030528 (H2724): A long GRB localized by HETE
  36. GRB 030329: Optical Observations
  37. GRB 030528: Optical observations at RIKEN
  38. GRB 030528 (=H2724) Kyoto optical observation
  39. GRB 030416: Optical Observations
  40. GRB 030329: optical photometry at various french observatories
  41. GRB 030329: optical photometry at Belesta observatory (France)
  42. GRB030329, Optical observations
  43. GRB 030329: HST ACS Observations of the Host
  44. GRB 030329 Optical Observations
  45. GRB030329: XMM-Newton observation
  46. GRB030324: Further Observations of the Candidate Optical Afterglow
  47. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  48. GRB 030418: Second Epoch Optical Observations with Magellan
  49. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  50. GRB 030329: Optical limit (contemporaneous imaging)
  51. GRB030329: RTT150 optical observations
  52. GRB030329, BVRI photometry
  53. GRB030429, refiend optical brightness
  54. GRB 030329: Optical limit (contemporaneous photography)
  55. GRB030418, BVRcIc field photometry
  56. GRB030429, BVRcIc field photometry
  57. GRB030429: RTT150 optical obs., correction to GCN 2208
  58. GRB 030329: High-Resolution Spectroscopy of the Host
  59. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  60. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  61. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  62. GRB030429: RTT150 optical observations, a possible host galaxy
  63. GRB030329: RTT150 optical observations and upper limit for a host
  64. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  65. GRB030501, optical observation
  66. GRB030501 observation report
  67. GRB030329: RTT150 optical observations and upper limit for a host
  68. GRB 030429: Radio Observations
  69. GRB 030429: redshift from VLT spectroscopy
  70. GRB 030329 Optical Observations
  71. GRB030328, optical observation
  72. GRB 030329, BVRI photometry
  73. GRB030429: Optical Observations
  74. GRB030501: TAROT candidate afterglow present in archival images
  75. GRB030429, possible optical counterpart
  76. GRB030425: CrAO optical observation
  77. GRB 030329 Oprical observations in Rozhen observatory
  78. GRB 030324: Radio Observations
  79. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  80. GRB030329, SPM optical observations (Correction)
  81. GRB030329, SPM optical observations
  82. GRB 030329: Spectral Evolution of SN 2003dh
  83. Optical Observations of GRB 030418 with Magellan
  84. GRB 030329: optical spectropolarimetry at VLT
  85. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  86. GRB030329: optical polarization
  87. GRB030329, optical observation
  88. ROTSE-III prompt optical detections of GRB 030418
  89. GRB030418: Upper limits from recent and historical observations.
  90. GRB 030418: Optical afterglow
  91. GRB 030418: Finder for afterglow candidate
  92. GRB 030418: Optical afterglow candidate
  93. GRB 030329 OT position
  94. GRB030329: Optical Observations
  95. OT GRB 030329: early UBVRcIc spectral evolution
  96. GRB030329, UBVRI polarimetry, R-polarization
  97. GRB 030329: SARA Optical Observations
  98. OT GRB 030329: early spectrum
  99. GRB030324: Candidate Optical Afterglow (Erratum)
  100. GRB030324: Candidate Optical Afterglow

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov