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').
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"42 results found.
- GRB 250215A / EP250215A: Encouraging Follow-up Observations of a BdHN I with a Rest-Frame Duration 2.3 s at z=4.61
- GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
- GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
- GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
- AT2023sva / GRB230916B: GIT observations of the afterglow
- transient AT2023sva: A Binary Driven Hypernova with a possible associated supernova
- GRB 230430A: A short GRB from a neutron star merger
- GRB 221009A: Determination of the black holes mass and spin
- GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
- GRB 221009A X-ray light-curve and the indication of TeV light-curve
- GRB 221009A: A type I BdHN of exceptional energetics
- GRB 220527A: A BdHN I with a clear UPE phase
- GRB 220101A: The first example of a Petanova
- GRB 220101A: The most powerful GRB and BDHN I in 26 years
- GRB 211023A: A BdHN of type I
- GRB 210411C: A very significant early X-ray afterglow
- GRB 210410A: A twin of short GRB 090510 with complementary observations
- GRB 210210A as a BdHN II
- GRB 190114C: A type 1 BdHN with TeV emission
- GRB 180728A: A long GRB of the X-ray flash (XRF) subclass, expecting supernova appearance
- GRB 180720B: Testing the universality of the newly born neutron star in BdHNe
- GRB 160521B: Theoretical estimate of the redshift and urgent need for further x-ray observations
- GRB 151027A: the missing GeV component
- GRB 150906B: Further analysis of the Konus-Wind data
- GRB 150906B - NGC 3313 association: Constraints from Ep-Eiso and Ep-Liso Relations
- GRB 150906B: theoretical estimation of redshift and isotropic energy
- GRB 150513A: request for X-ray follow up
- GRB 140206A: NOT redshift
- GRB 140206A: theoretical prediction of redshift and of supernova occurrence
- GRB 140108A: theoretical prediction of redshift and of supernova occurrence
- GRB131202A : GROND observations
- GRB 131202A: theoretical estimation of the redshift
- GRB 060614: theoretical derivation of the redshift and need for deeper search of the host galaxy
- GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
- GRB 130603B: Analogy with GRB 090510A and possible connection with a supernova
- GRB 130609B: Theoretical redshift estimation
- GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
- GRB 130427A: Predictions about the occurrence of a supernova
- GRB 121217A theoretical estimate of redshift and of supernova occurrence
- Redshift of GRB 110402A theoretically estimated (revised)
- Redshift of GRB 110402A theoretically estimated
- Request for Supernova related data for GRB 101023A