The gamma-ray burst GRB 000210 had the highest γ-ray peak flux of any event localized by BeppoSAX as yet but it did not have a detected optical afterglow, despite prompt and deep searches down to R lim ≈ 23.5. It is therefore one of the events recently classified as dark GRBs, whose origin is still unclear.

Chandra and XMM-Newton resolved extremely long tails behind two middle-aged pulsars, J1509-5850 and J1740+1000. The tail of PSR J1509-5850 is discernible up to 5.6 from the pulsar, which corresponds to the projected length l ⊥ = 6.5d 4 pc, where d = 4d 4 kpc is the distance to the pulsar. The observed tail flux is 2 × 10 −13 erg s −1 cm −2 in the 0.5-8 keV band. The tail spectrum fits an absorbed power-law (PL) model with the photon index Γ = 2.3 ± 0.2, corresponding to the 0.5-8 keV luminosity of 1 × 10 33 d 2 4 ergs s −1 , for n H = 2.

We report on two Chandra observations of the 3 Myr old pulsar B1929+10, which reveal a faint compact ($9 00 ; 5 00 ) nebula elongated in the direction perpendicular to the pulsar's proper motion, two patchy wings, and a possible short ($3 00 ) jet emerging from the pulsar. In addition, we detect a tail extending up to at least 4 0 in the direction opposite to the pulsar's proper motion, aligned with the $15 0 long tail detected in ROSAT and XMM-Newton observations. The overall morphology of the nebula suggests that the shocked pulsar wind is confined by the ram pressure due to the pulsar's supersonic speed. The shape of the compact nebula in the immediate vicinity of the pulsar seems to be consistent with the current MHD models. However, since these models do not account yet for the change of the flow velocity at larger distances from the pulsar, they are not able to constrain the extent of the long pulsar tail. The luminosity of the whole nebula as seen by Chandra is L PWN $ 10 30 ergs s À1 in the 0.3Y8 keV band, for the distance of 361 pc. Using the Chandra and XMM-Newton data, we found that the pulsar spectrum is composed of nonthermal (magnetospheric) and thermal components. The nonthermal component can be described by a power-law model with photon index À % 1:7 and luminosity L nonth PSR % 1:7 ; 10 30 ergs s À1 in the 0.3Y10 keV band. The blackbody fit for the thermal component, which presumably emerges from hot polar caps, gives the temperature kT % 0:3 keV and projected emitting area A ? $ 3 ; 10 3 m 2 , corresponding to the bolometric luminosity L bol $ (1Y2) ; 10 30 ergs s À1 .

An extensive collection of observational data is presented which indicates that the recently discovered infrared object Maffei 1 is a highly reddened giant elliptical galaxy at a distance of about 1 Mpc, and thus is probably a new massive member of the Local Group.

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