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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28277 results found.

  1. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  2. GRB 241104A: Swift-XRT observations
  3. GRB 240511A: LCO upper limits
  4. GRB 241104A: Fermi GBM Observation
  5. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  6. GRB 241104A: SVOM/VT optical candidate
  7. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  8. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  9. EP241104a: EP detection of GRB 241104A X-ray emission
  10. GRB 241010A: host galaxy redshift z = 0.977
  11. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  12. GRB 240821A: further radio observations with the VLA
  13. EP241103a: GIT optical upper limit
  14. EP241021a: OHP/T193 further optical observations
  15. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  16. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  17. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  18. EP241103a: Swift XRT detection and improved X-ray position
  19. EP241021a: continued SOAR observations
  20. EP241101a: Optical upper limits with Kinder observations
  21. EP241101a: OHP/T193 optical observations
  22. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  23. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  24. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  25. EP241103a: GSP optical upper limit
  26. EP241103A: LCO optical observations
  27. EP241103a: an X-ray transient detected by Einstein Probe
  28. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  29. S241102cy: Identification of a GW compact binary merger candidate
  30. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  31. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  32. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  33. GRB241030A: OHP/T193 optical observations
  34. GRB 241101A: FRAM-ORM optical limit
  35. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  36. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  37. EP241021a: Upper limit from Konus-Wind observations
  38. GRB 241101A: Swift-BAT refined analysis
  39. GRB 241030A: further SAO RAS optical observations
  40. GRB 241030A: Optical Observations via Virtual Telescope Project
  41. EP241021a: Liverpool Telescope optical follow-up observations
  42. GRB 241030B: Swift-XRT refined Analysis
  43. GRB 241026A: SAO RAS optical observations
  44. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  45. GRB 241101A: Swift detection of a burst
  46. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  47. EP241021a: OHP/T193 optical observations
  48. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  49. GRB 241030B: Montarrenti Observatory optical upper limit
  50. EP241026b: Liverpool Telescope optical follow-up
  51. GRB 241030A: SAO RAS optical observations
  52. GRB 241030A: Fermi GBM Observation
  53. EP241021a: AMI-LA radio detection
  54. GRB 241030B : GIT optical upper limits
  55. GRB 241030B: LCOGT Optical Upper Limits
  56. GRB 241030B: Swift-BAT refined analysis
  57. GRB 241030A: Swift-BAT refined analysis
  58. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  59. GRB 241030B: Swift/UVOT Detection
  60. GRB 241029A: LCO optical detection
  61. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  62. GRB 241030B : MITSuME Akeno optical upper limits
  63. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  64. GRB 241030B: SVOM/VT optical afterglow observations
  65. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  66. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  67. GRB241030B: Fermi GBM Observation
  68. GRB 241030B: BTA observations
  69. GRB 241029A: SVOM/VT optical afterglow observations
  70. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  71. GRB 241030B: Enhanced Swift-XRT position
  72. GRB241030B: GRANDMA/TAROT Upper Limit
  73. GRB 241030A: Swift-XRT refined Analysis
  74. GRB 241030B: SAO RAS optical observations
  75. GRB 241030B: AKO Optical Afterglow Detection
  76. GRB 241030B: Nanshan/HMT optical afterglow detection
  77. GRB 241030B: Swift detection of a burst
  78. GRB 240912A: radio detection with the VLA
  79. GRB 241030A: AKO Optical Afterglow Detection
  80. GRB 241030A: Swift/UVOT Detection
  81. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  82. GRB 241026A: Swift-BAT refined analysis
  83. GRB 241030A: SVOM/C-GFT optical observations
  84. GRB 241026A: LBT optical observations
  85. EP241021a: Optical rebrightening observations with Mephisto
  86. GRB 241030A: Multiband optical detection with Mephisto
  87. GRB 241030A: SVOM/VT optical afterglow observations
  88. GRB 241030A : MITSuME Akeno optical afterglow detection
  89. GRB 241030A: Enhanced Swift-XRT position
  90. GRB 241029A: GROWTH-India Telescope optical follow up
  91. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  92. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  93. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  94. GRB 241029A: SAO RAS optical observations
  95. GRB 241026A: SAO RAS optical observations
  96. EP241021a: SAO RAS observations of rebrightening
  97. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  98. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  99. GRB 241026A: Swift/UVOT Upper Limits
  100. GRB 241029A: Swift-XRT observations

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